Book summary “A history of Christianity”: summary

Introduction

You often view Christianity as a single monolithic block. Yet you actually face a vast, mutating global tradition with roots in three distinct language branches: Greek, Latin, and Syriac. You struggle to grasp how a small Jewish sect transformed into a global empire of faith that shapes modern culture.

Christianity is a vast, mutating global tradition shaped by its dual Greek and Jewish heritage, internal theological splits, and a constant tension between worldly power and spiritual faith.

Diarmaid MacCulloch traces this monumental history across three millennia. You will examine the foundational roots, the imperial transformation of the early church, the divergence of Eastern and Western Christendom, and the subsequent fracture caused by the Reformation and modern crises.

As you read, you will find answers to several major questions:

• How did Jewish monotheism merge with Greek philosophy to form Christian dogma?
• What caused the permanent fractures between Eastern Orthodoxy, Roman Catholicism, and Protestantism?
• How did a persecuted Mediterranean sect conquer empires and expand globally?
• In what ways does the modern secular world still operate on Christian assumptions?

1. Foundational Roots

Christianity's foundational concepts and earliest texts emerged from a complex synthesis of Greek philosophical vocabulary and ancient Jewish religious history. You find that the religion relies equally on Hellenistic reasoning and ancient Near Eastern scripture.

Christianity's foundational concepts and earliest texts were constructed using Greek terminology and philosophical ideas that intertwined with Jewish traditions.

The Apostle John opens his Gospel narrative with a hymn focused on logos, meaning speech, thought, or reason, and believers translated the Hebrew title Messiah into the Greek Christos. The earliest Christian texts were written in the Greek alphabetic script, and Revelation depicts Jesus using the Greek alphabet letters Alpha and Omega.

Christians adopted the Greek word ekklesia, originally signifying the assembly of citizens in a polis who met to make policy decisions, to describe their own communities and the universal Church. This democratic political legacy introduced a persistent tension between the collective responsibility of the assembled faithful and the authoritarian mastery implied by alternative terms like church or kirk.

Ancient Greeks recognized membership in an actual physical city as the defining trait raising humans above barbarism, a concept later adapted by Christians for their spiritual communities.

Socratic rational inquiry and Platonic idealism deeply influenced Western philosophy and Christian theological frameworks. Socrates championed logical argument and the principle that the unexamined life is not worth living. Plato introduced the theory of Forms, portraying the everyday world as mere shadows of a higher ultimate reality. Plato also conceived of a supreme, passionless God characterized by oneness and goodness, though separate from human emotion, which created theological dilemmas for early Christians.

Plato illustrated the human condition in The Republic through the allegory of the cave, where prisoners mistake shadows cast on a wall for true reality.

Historical records note specific dates for these philosophical figures:

• 469-399 BCE marks the lifespan of Socrates;
• 399 BCE is the year of his trial and execution;
• 428/7-348/7 BCE covers the lifespan of Plato.

A People and Their Land

The strategic geographical position of the Holy Land between major empires made it a constant battleground, permanently shaping the religious imagination of its inhabitants. Situated as a land bridge connecting Egypt to the Middle East, the region's narrow passes like Megiddo attracted endless foreign conquests. This historical trauma of great power conflicts inspired the concept of Armageddon as the ultimate cosmic battleground in religious texts.

The ancient strongpoint at Megiddo served as the chief passage point for land traffic and armies, leading directly to its symbolic immortalization as Armageddon in the Book of Revelation. The undivided Israel and Palestine region spanned a modest overall extent of 150 miles by 100 miles.

The foundational identity of ancient Israel emerged not from a single homogenous ethnicity, but from marginalized, uprooted social groups who united around a new god. Historical evidence and biblical echoes suggest that early Israelites originated from Habiru, representing marginalized nomads and dispossessed people on the edges of societies. They constructed a new identity sealed by a personal god who was not tied to older establishments.

The Egyptian Pharaoh Merneptah victory monument from 1216 BCE contains the first known non-biblical mention of Israel. The Book of Judges depicts the tribal confederation across the historical period from 1200 to 1050 BCE.

King David established Jerusalem as a unifying political capital and religious center by housing the Ark of the Covenant, creating a legacy that defined Jewish and Christian imagery. To prevent rivalries among various tribal groupings, the usurper-king David strategically selected Jerusalem as a neutral capital and relocated the sacred chest known as the Ark of the Covenant there. His son Solomon subsequently built the central Temple, anchoring the religious identity around Jerusalem.

King David brought the Ark of the Covenant to Jerusalem, and King Solomon built the first permanent Temple to house it. Solomon maintained a long reign from c. 970 to c. 930 BCE during which the united kingdom reached its greatest extent, while 150 songs or liturgical hymns were welded into the single book of psalms ascribed to David.

Faced with the terrifying threat of the Assyrian Empire, eighth-century prophets redefined religion by emphasizing social justice and demanding absolute obedience to Yahweh. Unlike court prophets who merely blessed national policies, independent prophets indicted entire societies for corruption and foreign contamination. They argued that national survival depended strictly on moral and religious obedience to a universal god of history.

The prophet Elijah engaged in a fierce religious showdown with Queen Jezebel, who had imported the worship of the fertility god Baal. The northern kingdom of Israel suffered destruction and exile by the Assyrians in 722 BCE.

The Babylonian exile catalyzed the canonization of sacred texts and provoked profound new theological questions regarding suffering, the afterlife, and cosmic adversaries. Displaced elites in Babylon preserved and edited their national traditions, establishing the Temple and scripture as the absolute centers of identity. The trauma of exile also stimulated new ideas about individual resurrection, the immortal soul derived from Greek philosophy, and the growing status of Satan as a cosmic adversary.

The Book of Job and the writings of Qoheleth explored deep existential questions and the problem of undeserved human suffering in the wake of national catastrophe. The Persian ruler Cyrus conquered Babylon in 539 BCE, allowing Jews to return home, and the rebuilt Temple in Jerusalem was reconsecrated in 516 BCE.

2. One Church and Imperial Transformation

The early Christian movement transitioned from a persecuted sect into an imperial church shaped by intense theological controversies and councils.

Beginnings and Shaping the Church

The four canonical Gospels are down-market biographies written decades after Jesus's death. They function more as theological good news than as objective historical reports. Matthew, Mark, Luke, and John wrote at least half a century after Jesus died. Their focus rests on ordinary people rather than the elite, fusing historic events with cosmic timelessness to convey theological meaning.

Jan Morris recalled a Sudanese minister advising her that foreign correspondents should report thrilling and good news that corresponds with truth. This advice provides a model for approaching the Gospels and their message of evangelion.

Paul of Tarsus transformed Christianity from a Jewish sect into a universal movement by preaching to non-Jews. He emphasized faith in Christ over the Mosaic Law. After a dramatic conversion experience on the road to Damascus, Paul focused his mission on Gentiles and Greek-speaking God-fearers known as theosebeis. He argued that humans cannot be justified through their own efforts or the Law, but only through total faith in the crucified and resurrected Christ. Paul accused his opponents, including the disciple Peter, of cowardice and inconsistency regarding table fellowship with Gentiles in Galatia. Three years passed before Paul's first encounter in Jerusalem with Peter and James.

Early Christianity transitioned rapidly from a rural Palestinian movement to an urban Graeco-Roman religion. Its leaders accommodated existing social hierarchies because they expected the world to end imminently. Paul's letters reveal that early Christian communities flourished in busy commercial centres and cities across the eastern Mediterranean. Because Paul and his followers assumed the imminent return of Christ, they did not challenge existing social structures or institutions like slavery. They advised everyone to remain in the social state in which they were called. Paul wrote to urban recipients such as Gaius, who hosted the entire local church, and Erastus, the city treasurer in Corinth.

When the Jewish revolt broke out in 66 CE in Palestine, the Jewish Christian community fled to Pella. The Roman destruction of Jerusalem in 70 CE and the second revolt in 132-5 CE crushed Jewish nationalism. The Pharisee leadership at Jamnia then tightened religious boundaries and marginalized Jewish Christians as heretical Ebionites. The second revolt resulted in the creation of Aelia Capitolina. Jerome later translated the Gospel according to the Hebrews used by surviving Jewish-Christian communities before they faded from history.

To counter gnosticism and Marcionism, the emerging Catholic Church consolidated its universal authority using four main tools:

• a defined canon of scriptures;
• standardized creeds;
• apostolic succession;
• a threefold ministry.

Faced with boundless disagreements, the mainstream church sought uniformity by establishing a New Testament canon alongside the Old Testament. It summarized standard beliefs in short instructional creeds to prevent speculation. The church then anchored governance in a monarchical episcopate. Bishop Ignatius of Antioch provided the first known use of the term katholike church, emphasizing that the congregation must follow the bishop just as the church follows Jesus Christ. Athanasius issued a pastoral letter in 367 CE containing the earliest surviving complete list of the New Testament books.

Constantine and the God of Battles

Constantine transformed Christianity from a persecuted minority faith into the favoured religion of the Roman Empire by associating his military victories with the Christian God.

Senior emperor Constantius I died in 306, and Constantine was proclaimed emperor at York. During his march on Rome in 312, Constantine attributed his victory at the Milvian Bridge to a vision of a cross of light. He commanded his troops to bear the Chi-Rho symbol on their shields. A joint declaration at Milan in 313 proclaimed equal toleration for Christians and non-Christians. Licinius was defeated and murdered in 324, ending the persecution crisis. Constantine subsequently showered privileges and wealth on the Christian clergy. He saw the Christian God not as a gentle pacifist, but as a potent God of Battles who could secure imperial stability. Constantine commissioned fifty monumental copies of the Bible from Bishop Eusebius's scriptorium in Caesarea, requiring parchment that consumed the skins of around five thousand cows.

To preserve imperial and ecclesiastical unity against doctrinal division, Constantine convened the first general council at Nicaea in 325. When the priest Arius argued that Christ was a created being subordinate to the Father, the resulting dispute fractured the Eastern Church. Constantine intervened by summoning the Council of Nicaea, where he successfully pushed for the insertion of the term homoousios into the official creed. This action outlawed subordinationist views and established a precedent for imperial enforcement of doctrine. Arius ultimately died an obscure death from an acute attack of dysentery in a latrine in Constantinople, an event commemorated with hostility in the Orthodox liturgy.

The ongoing Christological controversy between the Alexandrian school and the Antiochene school tore the Eastern Church apart. The Alexandrian school stressed a single composite nature, while the Antiochene school emphasized two distinct natures. The first Council of Ephesus met in 431, followed by the second Council of Ephesus in 449. Under imperial direction, the Council of Chalcedon in 451 forged a compromise definition upholding two natures in one hypostasis. This decision alienated Miaphysites and permanently fractured the Eastern Christian world. The disgraced former Bishop Nestorius died in exile just as a message reportedly arrived inviting him to participate in the Council of Chalcedon.

3. Eastern Realignment and Western Christendom

Following theological fractures and the rise of Islam, Christianity divided into distinct regional trajectories across the East, Byzantium, and the Latin West.

Operating independently of imperial politics, Syriac missionaries brought Christianity to Central Asia, India, and China. They operated as expatriate chaplaincies and integrated with local elites while maintaining Syriac as their common liturgical language.

A delegation led by a bishop named Alopen arrived in China in 635 and founded the first monastery in Chang'an.

Islam emerged in the seventh century through Muhammad's revelations, which were enshrined in the Qur'an and treated as a final divine revelation comparable to the incarnate Son in Christianity. Muhammad began receiving revelations in 610 in a cave near Mecca and dictated them to disciples. The Qur'an heavily references Jewish and Christian scriptures, prominently features figures like Mary, but strikingly omits Paul of Tarsus. It presents Islam not as a completely new message, but as the original monotheistic truth.

The name of Mary, the mother of Jesus, occurs almost twice as often in the Qur'an as in the New Testament and names one of its suras.

The rapid military expansion of early Islamic forces fundamentally shifted the center of Christian gravity westward by seizing traditional Christian heartlands in the Middle East and North Africa. Internal divisions within Christianity, such as conflicts between Chalcedonian rulers in Constantinople and local Miaphysite or Dyophysite populations, facilitated the swift Islamic conquests. Christians were classified as People of the Book and subjected to the dhimma system, allowing them to practice their religion privately in exchange for a specified tax burden.

In Egypt, excavations at the shrine of St Menas at Abu Mina show that the last Greek receipts for the wine harvest on pottery date precisely to the invasion year of 641, after which the Coptic Church took complete charge.

Islam and Eastern Missions

The bishops of Rome established their overriding authority in the Western Church by leveraging the charisma of the Apostle Peter's tomb rather than through exceptional theological contributions. Unlike Eastern centers of lively theological debate, Rome produced few major early theologians, relying instead on the tangible legacy of the Apostles Peter and Paul and the secular power vacuum left by Emperor Diocletian's administrative reorganization of the empire in the 290s.

Pope Damasus I leveraged the see's traditions by using imperial bureaucratic language, financing inscriptions at holy sites, and asserting that Peter was not only Rome's founder but its first bishop based on Matthew 16:17-19.

Augustine shaped Western Christian thought by formulating doctrines on original sin, the two cities, and a strict theology of predestination and grace in response to political collapse and heresy. Writing against the background of the sack of Rome in 410 and the Donatist and Pelagian controversies, Augustine argued that evil is the mere loss of good, that humanity is born entirely corrupted by Adam's sin, and that salvation depends completely on God's arbitrary predestination of an elect group.

Augustine experienced a conversion crisis in Milan in 386 after hearing a child chant tolle lege and reading Paul's Epistles, leading him to abandon his academic career and mistress.

The Rule of St. Benedict established a practical, highly adaptable framework for independent, community-based Western monastic life centered on disciplined obedience and labor. Drawing heavily on the earlier Rule of the Master, Benedict pruned and softened the requirements with common sense and kindness toward the sick, entirely rejecting the wandering holy men common in the East in favor of settled, self-contained communities under an abbot.

Monks within the Benedictine tradition creatively adapted Benedict's twin commands to labour and pray so that labor explicitly included scholarly text copying, preserving ancient texts for Western civilization.

• Live in a single community in obedience to its abbot.
• Follow a shared Rule that balances spiritual growth with community peace.
• Combine manual labor and prayer, adapting the routine to include scholarship.

The Rise of Papal Rome and Monasticism

Pope Gregory VII and reforming predecessors constructed a centralized papal monarchy asserting supreme spiritual and political authority over all earthly rulers. Rejecting secular control, popes claimed the title Vicar of Christ, established permanent courts and cardinal bureaucracies, and codified canon law to unify Christian jurisprudence under Rome.

Pope Gregory VII forced the excommunicated King Henry IV to wait barefoot in winter snow for three days at Canossa in 1077.

The papacy harnessed pilgrimage devotion and the concept of holy war to launch the Crusades, promising spiritual salvation and creating specialized military monastic orders. Pope Urban II leveraged appeals from Byzantium and fictitious pilgrim atrocities at Clermont in 1095 to launch the First Crusade, guaranteeing immediate entry to Heaven for those who died repentant.

Crusaders captured Jerusalem in 1099 following an epic siege, executing Muslim and Jewish inhabitants in a savage attack.

Celtic Christian monks developed a rigorous theology of moral struggle and introduced tariff books of penance that fundamentally shaped medieval Western pastoral practice. Celtic clergy created detailed manuals specifying exact scales of penance for particular sins, providing a concrete way for laypeople to lift the burden of guilt, which contrasted with Augustine's pure grace theology.

Monks on the Skellig Islands and leaders like Columba and Columbanus established intense monastic communities and traveled widely to renew the Christian world.

• Confess sins repeatedly to a priest.
• Consult tariff books or memory to determine the appropriate penance.
• Perform concrete and specified acts such as fasting or abstention from sex to atone for sins.

The Fourth Lateran Council of 1215 established universal requirements for annual confession and communion while defining the doctrine of transubstantiation using Aristotelian categories. Pope Innocent III convened the council to impose regulated holiness and uniformity. The council asserted that the bread and wine are changed in substance into the body and blood of Christ while their accidents remain unchanged, providing a philosophical framework for the Real Presence.

Juliana of Mount-Cornillon experienced visions that led to the establishment of the feast of Corpus Christi to celebrate the consecrated eucharistic elements.

• Receive the eucharistic elements at Mass at least once a year.
• Prepare for the encounter through confession to one's own priest preserving absolute secrecy.

Gregory Palamas successfully championed Hesychasm, a mystical tradition centered on silent prayer and the perception of uncreated divine light, which became officially embedded in Orthodoxy. Against critics like Barlaam of Calabria who argued God's essence is unknowable, Palamas maintained that through disciplined prayer, posture, and the Jesus Prayer, humans could experience the uncreated energy of God as seen on Mount Tabor.

The synodical trials of Barlaam and the subsequent formal vindication of Hesychasm at the Church council of 1351.

• Maintain appropriate physical posture and correct breathing during prayer.
• Repeat a single devotional phrase known as the Jesus Prayer, specifically Lord Jesus Christ, Son of the living God, have mercy on me.

4. Dismemberment, Global Expansion, and Modern Crisis

The late medieval and modern eras experienced the fracture of Western Christianity through the Reformation, global colonial expansion, and radical intellectual challenges.

Reformation and Confessionalization

Desiderius Erasmus promoted a cerebral, biblically grounded Christian humanism called philosophia Christi while critiquing popular ritualism and monasticism. Publishing a critical Greek New Testament in 1516, Erasmus sought to replace scholastic theology and mechanical devotions with inner piety and scriptural literacy. He favored princely reform and placed high optimism on human intellectual capacity, leaning on the theology of Origen rather than Augustine's pessimistic anthropology.

Erasmus mocked the physical excesses of late medieval pilgrimage sites like Walsingham and Canterbury in his satirical Colloquies.

Martin Luther revolutionized Western soteriology by asserting that justification comes solely through faith and God's grace rather than human works or merit. Luther rejected the scholastic framework and the nominalist idea of a salvation contract, concluding instead that fallen humans are entirely trapped in sin and can do nothing to earn salvation. God imputes the merits of Christ to believers, declaring them righteous rather than making them inherently so through penance.

Luther experienced his breakthrough while lecturing on Paul's letter to the Romans, specifically reflecting on Romans 1.17 and realizing that righteousness is a free gift received through faith.

Ignatius of Loyola founded the Society of Jesus, creating a highly adaptable religious order designed for active ministry, education, and direct obedience to the Superior-General rather than traditional monastic enclosure. Following a spiritual crisis during his convalescence from a severe war wound, Ignatius wrote the Spiritual Exercises as a systematic guide for spiritual directors. The Jesuits avoided traditional monastic choir, distinctive habits, and inquisitorial duties, focusing instead on elite and secondary education to win back European elites.

• Use the Spiritual Exercises as a technical manual for clerical spiritual directors guiding others through prayer and self-examination.
• Adapt the Exercises at whatever level is appropriate for those seeking to benefit from them.

King Henry VIII broke England's ties with Rome to secure a royal divorce, enabling Thomas Cromwell and Thomas Cranmer to dismantle traditional religion. Frustrated by the Pope's refusal to annul his marriage to Catherine of Aragon, Henry used Parliament to repudiate papal jurisdiction. Under his ministers, monasteries were dissolved, and vernacular Bibles based largely on William Tyndale's translation were placed in every parish church.

William Tyndale spent his life translating the Bible into English before being kidnapped in Antwerp, strangled at the stake, and burned near Brussels. 16,000 copies of his New Testament translation arrived in England between 1526 and 1536. Between 1532 and 1540, English monasteries, nunneries, and friaries experienced swift dissolution.

John Calvin systematized Protestant theology in his Institutes and established a disciplined presbyterian church structure in Geneva that heavily influenced international Protestantism. Calvin emphasized God's absolute sovereignty and double predestination. In Geneva, he instituted a fourfold ministry of pastors, doctors, elders, and deacons governed through a disciplinary committee called a consistory, which served as a blueprint for Reformed churches in France, the Netherlands, and Scotland.

Calvin had the Spanish radical Michael Servetus burned at the stake in 1553 for denying the conventional doctrine of the Trinity, proving Protestants were as committed to traditional Christology as Catholics. In 1541, Genevan authorities ordered Calvin to draft the Ecclesiastical Ordinances.

Global Missions and Modern Secularization

Spain and Portugal initiated global missions by extending their domestic crusading ethos overseas, leading to a massive expansion of Western Catholicism. Forced by agricultural poverty and exposed Atlantic positions, the Portuguese pioneered maritime routes to Africa, India, and China, accompanied by religious intolerance. Meanwhile, Spanish conquests in the Americas under adventurers like Cortés and Pizarro operated under the rhetoric of the Reconquista.

In 1510, the Portuguese established a secure base in Goa, massacred six thousand Muslims, and later banned the practice of Hinduism. The Portuguese captured the Moroccan commercial centre of Ceuta in 1415, reached India in 1498, made their first landing on the east coast of Brazil in 1500, and sailed around the Chinese coast in 1513.

European Christian missions in Africa were severely undermined by their direct involvement in the Portuguese transatlantic slave trade, though some indigenous kingdoms voluntarily adopted Catholicism. Millions of Africans were shipped to American plantations to sustain colonial economies. While some clergy like Alonso de Sandoval ministered to arriving slaves, the Church's complicity in slavery made native populations deeply distrustful of Christianity.

The Central African kingdom of Kongo voluntarily adopted Catholicism under rulers like Afonso I, creating an indigenous Church despite resistance from Portuguese authorities over appointments. Three point five million people were shipped to Portuguese Brazil over three centuries. In 1686, the Roman Inquisition issued an unprecedented general condemnation of the slave trade.

The suppression of aristocratic clerical leadership and the challenges of the revolutionary era led the Roman Catholic Church to centralize power around the papacy through a movement known as ultramontanism. By looking beyond national borders to the pope as the ultimate spiritual patron, Catholics turned away from traditional aristocratic leaders and localist traditions like Gallicanism. This centralization culminated in Pope Pius IX declaring papal infallibility and issuing the Syllabus of Errors to condemn modern liberalism and progress.

Emperor Francis Joseph of Austria-Hungary exercised a traditional veto against a likely papal candidate in the papal election of 1903. The year 1815 marked the turning point after which ultramontanism represented innovation and Church reconstruction. In 1864, Pius IX issued the encyclical letter with the attached Syllabus of Errors. In December 1869, seven hundred bishops arrived at the Vatican for the council, and by July 1870, the vast majority backed the decree Pastor aeternus.

Nineteenth-century developments in geology, evolutionary biology, and higher biblical criticism severely challenged traditional Christian assumptions about divine creation and textual inerrancy. Charles Darwin's theory of natural selection presented a universe driven by amoral struggle rather than benevolent divine watchmaking. Simultaneously, scholars like David Friedrich Strauss applied Hegelian analysis to treat New Testament narratives as mythological symbols rather than literal history, prompting polarized reactions ranging from liberal theological adaptation to rigid Fundamentalism.

Darwin published On the Origin of Species in 1859, concluding with a lyrical reference to the grandeur breathed into life by the Creator. In 1835, David Friedrich Strauss published Das Leben Jesu.

The First World War destroyed the fifteen-hundred-year-old union between Christianity and secular power, ending the alliance between emperors and bishops. The collapse of the German, Austro-Hungarian, Russian, and Ottoman empires removed the crowned heads that traditionally sustained state churches, leaving Christendom as a ghost by the late 1960s.

Village parish churches across Britain and Europe became the primary settings for community war memorials, such as the list of sixteen dead men in Wetherden or twenty-nine in Haughley, reflecting the transition of war remembrance into a civic-religious national ritual.

The Second Vatican Council fundamentally transformed Roman Catholicism by opening dialogue with the modern world, embracing vernacular liturgy, and redefining the Church as the People of God. Convened by Pope John XXIII, the council rejected defensive Curial drafts and promulgated documents like Lumen Gentium, which introduced the concept of collegiality among bishops and stated that the Church subsisted in the Roman Catholic Church rather than being identical to it. It also altered liturgical practices by replacing the Latin Tridentine Mass with vernacular services where priests faced the congregation.

Pope John XXIII surprised the church establishment by inviting Protestant observers and women, largely nuns, to attend the council proceedings. In 1959, Pope John XXIII announced the new council, and by 1962, more than two thousand bishops arrived in Rome.

10 Key Ideas

1. Christianity's foundational concepts and earliest texts were constructed using Greek terminology and philosophical ideas that intertwined with ancient Jewish traditions.
2. Constantine transformed Christianity from a persecuted minority faith into the favoured religion of the Roman Empire by associating his military victories with the Christian God.
3. Following theological fractures and the rise of Islam, Christianity divided into distinct regional trajectories across the East, Byzantium, and the Latin West.
4. Augustine shaped Western Christian thought by formulating doctrines on original sin, the two cities, and a strict theology of predestination and grace in response to political collapse and heresy.
5. Pope Gregory VII and reforming predecessors constructed a centralized papal monarchy asserting supreme spiritual and political authority over all earthly rulers.
6. Desiderius Erasmus promoted a cerebral, biblically grounded Christian humanism called philosophia Christi while critiquing popular ritualism and monasticism.
7. Spain and Portugal initiated global missions by extending their domestic crusading ethos overseas, leading to a massive expansion of Western Catholicism.
8. Nineteenth-century developments in geology, evolutionary biology, and higher biblical criticism severely challenged traditional Christian assumptions about divine creation and textual inerrancy.
9. The First World War destroyed the fifteen-hundred-year-old union between Christianity and secular power, ending the alliance between emperors and bishops.
10. The Second Vatican Council fundamentally transformed Roman Catholicism by opening dialogue with the modern world, embracing vernacular liturgy, and redefining the Church as the People of God.