By Sarah Harvey
Christianity is the world’s largest religious tradition with 2.5 billion followers, about 30 per cent of the world’s population in 2020. It is also the largest religion in the UK — 46.2 per cent of the population of England and Wales are Christian, according to the 2021 census.
How did Christianity start?
Christianity is based on the life and teachings of Jesus of Nazareth, who lived in the Middle East 2,000 years ago from 0-33CE. It has its origins in Judaism — Jesus and his early followers were Jewish. Christianity developed as a distinct religious movement gradually after Jesus’s death.
After his death by crucifixion, the description of Jesus’s resurrection, his physical reappearance to some of his disciples, and ascension into heaven, are key elements in Christian belief. After the resurrection, the disciples proclaimed Jesus as the Anointed One, called the Messiah in the Jewish tradition and the Christ in Greek, and launched a public ministry on the Jewish festival of Pentecost, when the gifts of the Holy Spirit are said to have descended upon those gathered. The church — the community of those who believed the Christian message — began to spread beyond Jerusalem and it was then that the followers were first called Christians, followers of the Christ.
What do Christians believe?
Christians believe the Bible to be divinely inspired, the word of God. However, interpretations of the text range from a literal interpretation of the Bible to more metaphorical or contextual interpretations. The Christian Bible is not a single book but a collection of writings of different formats including stories, poetry, songs, letters and historical writings. It is divided into two main sections: the Old Testament, which is shared with the Jewish tradition, and the New Testament. There are numerous translations of the Bible, and different traditions tend to favour some over others.
A number of core beliefs are shared by the Christian traditions and others vary according to denomination. Shared beliefs are around the person of Jesus and his role in humanity’s salvation and around the Bible as the word of God.
Christianity is a monotheistic faith — followers believe in one God — and the majority of Christian traditions teach that the one God is known in three persons: the Father, the Son (Jesus Christ) and the Holy Spirit. This doctrine, known as the Trinity, is expressed in the Nicene Creed, a widely accepted Christian statement of faith dating from the fourth century.
Christians believe that Jesus is the Messiah prophesied in the Hebrew Bible, come to earth to fulfil God’s law and to teach love of God and love of your neighbour. Christians also believe that Jesus is God incarnate — that he was simultaneously fully human and fully divine. They hold that he was born of Mary and was conceived by the power of the Holy Spirit. The Holy Spirit is believed to be God’s continual presence on earth and this is particularly emphasised in the Pentecostal traditions.
Christians believe in salvation through Jesus — that Jesus died on the cross for the sins of humankind and brought atonement (reconciliation with God). Humanity had been separated from God through sin, beginning with the fall of Adam and Eve in the Garden of Eden. While Christians agree that Jesus is the saviour of humankind, there are different understandings as to what this means and whether belief in Jesus is all that is needed for salvation.
The nature of the Christian belief of life after death varies between traditions and individuals. One understanding is that that through Jesus’s death and resurrection, Christians too can be resurrected to a new life after the death of their physical body. Many believe that they will be judged by God and sent to heaven or hell, with the expectation that Christians will go to heaven as they have been granted forgiveness through Christ.
Christians also believe, whether metaphorically or literally, in the “end times”, in the return of Jesus and the establishment of the kingdom of God on earth. These beliefs are termed millennialism and are often a peripheral rather than a central focus of Christian belief.
How do Christians practise their faith?
Christian worship includes both individual and collective practices. Individual practices include prayer, Bible study and, in some traditions, fasting. Collective worship includes attending church services, usually on a Sunday — the Sabbath day in most Christian traditions. Services include prayer, song, the reading of scripture, and a teaching or sermon by the priest/minister/pastor. They may include the Eucharist — the communion service when bread and wine is eaten and drunk together.
Most Christian groups hold additional services and events throughout the week, including midweek Bible study, prayer groups of different kinds, discussion groups, women’s groups, men’s groups, youth groups and more.
Many Christian traditions perform a number of “sacraments” or “sacred rites”. The Roman Catholic and Orthodox churches both recognise seven main sacraments, while the Protestant churches recognise two primary sacraments — baptism and the Eucharist — and a number of “lesser” sacraments.
Most traditions practise some form of baptism as constituting membership of their particular church, although the specific practices vary. The Catholic, Orthodox and Anglican churches all practise baptism of infants. Churches from the Anabaptist tradition, as well as churches within Pentecostal, charismatic and evangelical traditions, practise only adult baptism, sometimes known as “believers’ baptism”.
The majority of traditions celebrate the Eucharist in some form. This rite is also known as (holy) communion or the Lord’s Supper and it repeats the words and actions that Jesus is believed to have used at the last meal with his disciples before the crucifixion. Bread and wine, representing the body and blood of Jesus, is consumed.
The Roman Catholic Church teaches that when the priest repeats Jesus’s words from the Last Supper, the consecrated bread and wine become the actual body and blood of Jesus, although there is no change in their outward appearance. This is known as transubstantiation.
Other sacraments include:
- Confirmation: in which the believer makes a commitment to God, receives the gifts of the Holy Spirit and may be anointed with oil, also called chrismation in the Orthodox tradition.
- Reconciliation: with God, through confession of sins and absolution, which may include prayer and/or making the sign of the cross, also called confession or penance.
- Anointment of the sick: often with oil, also called holy unction.
- Marriage: the joining of a man and a woman in holy matrimony in most traditions.
- Ordination: laying on of hands and anointing with oil for those who choose to join the priesthood, also called ministry or holy orders.
- In many Christian liturgical calendars there are six seasons: Advent, Christmas, Epiphany, Lent, Easter and Pentecost, with numerous other festivals, holy days and saints’ days. Very few Christian groups and individuals celebrate every holy day.
Where do the different denominations come from?
In the fourth to eighth centuries, seven ecumenical councils were held to define the orthodox teachings of the church and to quash perceived heresies.
However, differences between Christians in the Eastern Empire (with a seat of power in Constantinople and a primary language of Greek) and the Western Empire (based in Rome and with a primary language of Latin), intensified over the next few centuries leading, in 1054, to an official split into the Eastern Orthodox Churches and the Roman Catholic Church. This split is known as the Great Schism.
The 16th century saw the Protestant Reformation and the subsequent establishment of Protestant denominations including Anglican, Methodist, Baptist and Adventist traditions. The 20th century saw the rise of Pentecostalism which simultaneously created new denominations and was a movement of renewal or revivalism within existing traditions.
The Roman Catholic Church
The Roman Catholic Church sees itself as the church established directly by Jesus. It remains distinguishable by the office of Papacy: the Pope is the visible head of the church and is believed to have an unbroken line of succession from St Peter. The Pope is believed to be infallible when he speaks ex cathedra (“from the chair”) when defining a doctrine for the whole church.
Half the global Christian population is Catholic, accounting for about 1.2 billion people worldwide. There are about six million Catholics in England, Wales and Scotland — about 25 per cent of the UK’s Christians — with weekly mass attendance at just over one million.
Orthodox churches
The Orthodox churches do not constitute a single church with a single leader. Instead, Eastern Orthodoxy is described as a communion of churches, including autocephalous churches, each of which is led by a head bishop called patriarch, archbishop or metropolitan depending on the church; and autonomous churches, whose head bishop is appointed by a patriarch. Autocephalous churches include the Russian Orthodox Church — the largest Eastern Orthodox Church — and the Greek Orthodox Church. Autonomous churches include the Church of Finland and the Church of Sinai.
There are about 260 million Eastern Orthodox Christians worldwide, with concentrations in Russia, Ukraine, Romania, Greece, Serbia and Bulgaria.
There are also about 60 million non-Chalcedonian, sometimes called Oriental, Orthodox Christians worldwide with concentrations in Ethiopia and Egypt. These include the Coptic Orthodox Church, Ethiopian Orthodox Church and Armenian Apostolic Church. Together, the Orthodox churches constitute about 12 per cent of the world’s Christian population.
Protestant churches
The origins of the Protestant Reformation are often traced to Martin Luther pinning a set of theses on the door of a chapel in Germany in 1517. Whether this happened is a matter of some debate, although there had been calls for reform of the Roman Catholic Church for at least 200 years before this.
The distinguishing beliefs of the Protestant Reformation include: “the priesthood of all believers” — equality of believers, each with access to God and so not in need of mediation by a priest; belief in the Bible as the ultimate authority in matters of faith — sola scriptura or “by scripture alone”; and sola fide — justification in God’s eyes “by faith alone”.
There were about 800 million Protestants worldwide in 2011 — about 37 per cent of the world’s Christian population. Protestant denominations include the Anglican Church, Baptist churches, the Methodist Church, the Seventh-day Adventist Church and more.
The Anglican Church
The Anglican Church includes those churches in communion with the Archbishop of Canterbury. This includes the Church of England, created by Henry VIII in the 16th century. The Church of England remains the established church in England: the monarch is the supreme head and 26 bishops sit in the House of Lords.
The Church of England claims that more than 40 per cent of the population in England are members of the church. However, regular church attendance is only about a million people attending Sunday services.
The Anglican Communion, the worldwide fellowship of Anglican churches, is active in more than 165 countries and represents 85 million people.
Evangelical churches
Evangelical Christianity emerged in the 18th century. The term derives from the Greek euangelos which eventually refers to the Gospel, the “Good News of Jesus Christ” and at the most basic level refers to one who spreads the Gospel.
In general, evangelicals share a number of key beliefs rooted in the view that the Bible is the direct and inerrant word of God and hence the ultimate authority and guide for living. Evangelicals, in general, tend to have a literal interpretation of the Bible as the Word of God. The believe that Jesus died for our sins and salvation is for anyone who accepts Jesus into their lives and turns away from a life of sin. Christians should be “born again” as adults and can and should have a personal relationship with Jesus. Christians should live a life of example and should work towards the transformation of society for the better, which is tied to the mission of spreading the Gospel. Sometimes it is believed that spreading the Gospel will lead to transformation, but many evangelicals are also involved in charitable work.
Evangelicals can be found within all Christian traditions and evangelicalism can also be considered a tradition in its own right. Many non-denominational churches, including the majority of American “megachurches”, are evangelical in outlook. There are an estimated one billion evangelicals worldwide.
Pentecostal and charismatic churches
Pentecostalism began as a revival movement within the Protestant tradition, specifically within the Holiness churches of Methodism, in the United States in the 1900s.
The name is derived from the festival of Pentecost, when the gifts of the Holy Spirit are said to have descended upon Jesus’s disciples, and Pentecostalism is characterised by the conviction that every believer has a direct relationship with God and access to these gifts, which include glossolalia (speaking in tongues), prophecy and healing.
Pentecostal churches are likely to practise tithing in which members dedicate 10 per cent of their income to the church and some Pentecostal churches hold “prosperity theology” beliefs (sometimes known as the health and wealth gospel). Prosperity theology is the belief that faith, material donations and positive confessions increase one’s material wealth and physical wellbeing.
In 2011, there were 279 million Pentecostal Christians and 305 million charismatic Christians in the world, together accounting for 27 per cent of the Christian population. The largest numbers are found in the Americas and Sub-Saharan Africa.
African-Initiated churches
Half of the African population was Christian in 2020. Sub-Saharan Africa is home to 500 million Christians, almost a quarter (24 per cent) of the world population of Christians, with Nigeria, Democratic Republic of Congo and Ethiopia having the highest numbers.
The theologian Professor Allan Anderson of Birmingham University has categorised African Independent/Initiated Churches (AICs) into three broad types:
- “African churches”, which model themselves on the European mission churches from which they have seceded.
- “Prophet-healing”, “spiritual churches” or “African Pentecostal churches”. These have their roots in western Pentecostalism but also have significant differences such as: healing through the use of prophets and/or symbolic objects; strict prohibitions on alcohol, tobacco and pork; and dress codes, often white robes or military-style uniforms depending on the church.
- Newer Pentecostal and charismatic churches are of more recent origin than the African Pentecostal churches that emerged from the late 1970s and are more influenced by North American neo-Pentecostal developments such as prosperity theology. These churches often prohibit the distinctive elements of the African Pentecostal churches listed above and are more often led by young, charismatic, well-educated Africans. They are generally socially conservative in outlook and theologically have a focus on spiritual power, miracles and healing.
Contemporary issues
Some of the most pressing issues in worldwide Christianity today include the status of women and of LGBTQ+ members. While the Roman Catholic Church has rejected the ordination of women into the priesthood and condemns homosexual behaviour, the Anglican Church has ordained both female and LGBTQ+ clergy.
The biggest scandal to hit the Roman Catholic Church in recent years has been the uncovering of child abuse cases in several countries. These cases range from the sexual abuse of children by individual priests to the endemic physical and sexual abuse of children in Catholic schools and other institutional settings in Ireland and America. Cases have been brought against individual priests as well as against the church hierarchy for failing to deal with the issue and for not taking cases to the legal authorities. There have also been cases in the Anglican Church, Baptist Church, the Methodist Church, Jehovah’s Witnesses and in newer movements such as the Jesus Fellowship, which shut in 2019.
While Christianity is the majority religion in many countries worldwide, in some countries Christians face persecution as members of a minority religion. Christians are persecuted in North Korea, Afghanistan, Somalia, Libya and Pakistan. Additionally, particular minority Christian movements can face significant persecution in other countries such as Russia or China.
Dr Sarah Harvey is senior research officer at Inform, an independent, educational charity based at King’s College London, which provides information about minority religious, spiritual and political movements
Academic experts
Stephen Pattison, emeritus professor of religion, ethics and practice, HG Wood professor of theology, Birmingham University
Diarmaid McCulloch, professor of the history of the church, Oxford University
Professor Linda Woodhead, department of politics, philosophy and religion, Lancaster University
Dr George Chryssides, honorary research fellow at York St John University and Birmingham University
Dr Anna Strhan, department of sociology, York University
Further information
Adogame, Afe (2013) The African Christian Diaspora: New Currents and Emerging Trends in World Christianity. Bloomsbury Publishing
Anderson, Allan H. (2004) An Introduction to Pentecostalism: Global Charismatic Christianity. Cambridge University Press
Buckley, J. J., Bauerschmidt, F. C. et al., Eds. (2004) The Blackwell Companion to Catholicism. Blackwell Companions to Religion, Blackwell
Chryssides, George D. and Wilkins, Margaret Z. (2014) Christians in the Twenty-first Century. Routledge
Guest, Mathew, Olson, Elizabeth and Wolfe, John (2012) “Christianity: Loss of Monopoly” in Religion and Change in Modern Britain, edited by Linda Woodhead and Rebecca Catto. Routledge, 57-79
Kay, William K. (2007) Apostolic Networks in Britain: New Ways of Being Church. Paternoster Press
MacCulloch, Diarmaid. (2009) A History of Christianity: The First Three Thousand Years. Penguin: London
Martin, David (2001) Pentecostalism: The World Their Parish. Wiley-Blackwell
Poloma, Margaret M. and Green, John C. (2010) The Assemblies of God: Godly Love and the Revitalization of American Pentecostalism. New York University Press
Strhan, Anna (2015) Aliens and Strangers? The Struggle for Coherence in the Everyday Lives of Evangelicals. Oxford: Oxford University Press
Ware, Timothy (1980) The Orthodox Church. Harmondsworth: Penguin
Woodhead, Linda (2004) Christianity: A Very Short Introduction. Oxford University Press
