What is a global history of Christianity? Most traditional Church history books are effectively the history of the European Church or a global history of specific Church traditions. In the recent past, historians have begun to write geographically specific histories of the Church in Asia (Samuel Moffett), in Africa (Elizabeth Isichei) and in Latin-America (Enrique Dussel). Others have attempted sweeping surveys of Christianity around the world (Kenneth Latourette, John McManners, and Adrian Hastings). Still others have offered evolutionary accounts of Christian thought (Jaroslave Pelikan). This prompted me to think of the Christian experience as a global rather than an isolated and strictly religious geographical history. As for the choice of using the word Christianity over the word Church, I wanted to write about the events and experiences of people who identified themselves as Christians, whether or not their detractors thought they were part of the church. However, there are boundaries to what a Christian believes in. I consider the minimal set of beliefs to include a Trinitarian creator, the incarnation of the Logos as the Christ, the reality of spiritual estrangement from and the promise of full reconciliation with God. Hence, a global history of Christianity attests to the experiences of people who identified themselves as followers of The Way in Jerusalem and expanded to become the world theological religion called Christianity. This definition of Christianity will necessarily exclude some radical Universalists, Unitarians or strict monotheists, and radical pantheists, because the Bible is clear that not everyone is saved, that God is Trinitarian and that God and creation are distinct. It is this definition of Christianity that we wish to examine.
 Religions that are not theological do not speak of worshipping a transcendent god, whether a creator or not.
 In this view, there is no distinction in the postmortem existence between a Christian and every other human, religious or not.
 In this view, God consists of a single person so that the Holy Spirit and Jesus are not recognized as divine beings.
 In this view, God and creation arise from a single reality with independent consciousness but share an identical essence.
I have set out to capture a history of Jesus’ followers across the world in four movements, set approximately 500 years apart. My thesis is that significant geohistorical changes fueled by emerging political consciousness, scientific inference, missional impulse and technologies in the 6th, the 11th, the 16th and the 21st centuries shaped the trajectory and self-understanding of Christians.
This global history of Christianity does not seek to be comprehensive or denominational, but to identify and appraise the influences that shaped the forces of belief in Jesus Christ around the world. In this sense, it is also a history of missions.
The second 500 years were influenced by the cooperation and competition between Church and State as divine religious authorities met the exertions of secular political power. The Christian faith was now represented by three traditions, the Chalcedonian, the Miaphysites and the Dyophysites.
- Missions to the China Sea and the Indian Ocean
The 6th to the 11th centuries saw the expansion of Christianity through missionary enterprises beyond the Roman Byzantine Empire. Africa and India were already Christianized but China remained uncharted territory. Three influences contended with the Christian message – the ancient philosophy of Buddhism in the Far East, Hinduism in the South and Islam in the Near East. In Europe, the alliance between the sacred and the secular culminated in the coronation of King Charlemagne of the Franks as the first Holy Roman Emperor (Imperator Romanorum) by Pope Leo the Great.
- Asia Minor: Byzantine Christendom
The Greek-speaking Byzantine Church of Eastern Europe took a separate pathway from its Latin-speaking, barbarian-ridden brothers in the west. Seeking mystical union with God, theosis, it shunned mere doctrines for a life of ritualistic worship.
- South East: Encountering Hinduism in India
The discovery of Thomas Christians who trace their history back to the first century of Christianity astounded the Western church. Today, the Malabar coast is home to the vibrant faith of Syriac rite traditions.
- Far East: Encountering Buddhism in China
There has been Christian presence in China since the 6th century. But in 635, the amazing intercontinental missionary journey of a Persian monk who traversed the Silk Route some 600 years before Marco Polo, established a faith tradition that ushered in the first Christian age of China.
- Near East: Encountering Islam in Persia
Islam possesses special links to Christian history, for it sees itself as a corrective to the faulty Christian doctrines of the Judaic faith. Its doctrines and practice mimic those of Christianity and many of its weaknesses can be traced to the weaknesses of the Christian church. The Muslims call the Islamic ‘voice of God’, the Ayat Allah, or Ayatollah. The rapid expansion of Islam brought most of Central Asia and Asia Minor to its knees. Baghdad became the center of Muslim thought and culture as well as Islamic law.
- Europe: Emperor and Pope
Charlemagne’s coronation by Leo III transformed the papacy and ushered in an age of unprecedented secular power for the bishopric of Rome and sacred authority for the new Holy Roman Emperor. The bishop became an emperor-maker and the emperor became the bishop-maker. The Roman bishops became landowners and territorial kings, mimicking the cry of the Israelites to have a king, [to be] ‘just like the other nations’. The bishop now enjoyed a status that approximated Augustus Caesar’s, ‘Son of a God’. In time, the bishop of Rome would become ‘Pope’.
Conclusion: Authority versus Power
This second 500-year period of Christianity was dominated by the struggle between proclamations of divine religious authority versus exertions of human political power. In China and Europe, Church and State grew in tandem until the fall of the Tang Dynasty and the start of the Crusades. Meanwhile, the State Religion of Islam swept through Europe and the Near East with an integrated mission, to bring the kingdom of God to Earth. Locked in battle for land in Europe, Christianity and Islam eventually clashed in Palestine over the Christian War Pilgrimage that was known to Muslims as the Great Christian Invasion – the Latin Crusades. Finally, the Christianization of Europe and the militarization of the Papacy initiated the rise of Christendom.