Christianity has existed in Africa arguably since a decade after the death of Jesus of Nazareth. With strong cultural ties between Roman Judea (Israel) and the Greco-Roman Egypt (a large Jewish population lived in Alexandria, Egypt), Mark the Evangelist established a church in Alexandria as early as 43 CE. Thereafter, Egypt became a hub for African Christianity, though it was intermittently subject to persecution by the oscillating preferences of Roman emperors. Not until the formalizing of Christianity as the empire's religion by Constantine was there a semblance of relief. From there, the religion spread down the Nile River Valley and into contemporary Ethiopia. There too the religion was subject to persecution, but around the same time as the rise of Constantine the religion won official recognition and the Ethiopian Orthodox Tewahedo Church was established.
Egypt was also an important setting as the refuge and hub of gnostic Christianity. There, either divergent movements of Judaism encountered Christianity or a new gnostic doctrine developed in tandem with the Egyptian Christian presence. From the second through the fourth centuries of the Common Era, a number of teachings called the Gnostic Gospels were written that purported to be teachings from Jesus, his disciples and other contemporaries. There may have been influence on the later Coptic Church. Early on, locations like Carthage also proved important to the development of Christianity, becoming the home of St. Augustine and his major ideological contributions to the religion.
Christianity from these areas spread into Africa, across the North and into the Sub-Sahara. Christians are said to have been encountered by Muhammad while in exile in Ethiopia. With the victory of Islamic forces in Arabia, Christianity faced substantial defections and threats by the wars of the Rashidun Caliphate with Byzantium and the invasion of Egypt. Despite the minimal numbers of converts and new settlers, Muslim armies were deployed rapidly to conquer large areas. Despite the heavy efforts to conquer southern Sudan, Egyptian Arab commanders began to conclude a number of agreements that maintained a status quo in the region for centuries. However, tax incentives eventually led to the conversion of many more of the region's Christians and animists to Islam. Nevertheless, the bulk of Africa has been converted to Christianity and not Islam, mostly in the Sub-Sahara. Islam has remained largely confined to the Sahara and the northern Mediterranean coast.
Africa, along with Latin America, has taken on a much larger role in contemporary Christian politics and activism. Disproportionately plagued by conflict and famine, it has been the focus of religious charity work for decades, with ads prominently displayed on television in the United States asking for donations to Christian relief organizations. Politically, it has been said the decline of Catholic observance in the West, particularly Europe, has given rise to the possibility that a Latin American or African Pope might be elected in the near future as both a natural development and way of invigorating the growth of Catholicism on the continent. Janet Jere, in an article showcasing Cardinal Arinze of Nigeria as a potential candidate for the papacy in 2003, highlighted the doubling of African Catholics over a 30-year period to more than 100,000,000. Additionally, she notes that half of Africa's Christian population is Catholic.
Philip Jenkins highlights the growth of Christianity in Africa, projected to continue well into the 21st century. In particular, he notes the growth of African churches detached from Western mission churches. This is a point similar to one made by Jere, both of them seeing the development of indigenous African styles of Christianity that are relevant both on the continent and globally. Jere suggests the appointment of an African Pope might allow the incorporation of African culture and styles of worship into African Catholic practices as mandated by the Church. Jenkins also suggests the growth of Christianity in the Third World generally will conflict with Islam and give rise to more ethnoreligious conflict.
David Barrett sees the development of these African indigenous churches as akin to the schisms of the Protestant movement in 16th-century Europe. Coincidentally, he comments, many would say their movements constitute "a reformation of over-Europeanized Christianity." In a sense, this can be related the phenomenon of post-colonialism, though in a unique religious form. This also marks the decline of Western Christianity thanks to secularism and non-observance, making resistance to an African Reformation relatively weak.