Christianity Today and Tomorrow

The world's largest faith

As of the mid-2020s, about 2.6 billion people identify as Christians, roughly 31 percent of the world's population. That share has been remarkably stable for a century, even as the location of Christians has shifted dramatically (see The Global South). Roughly speaking, and estimates vary:

• about half are Catholic (around 1.4 billion);
• about 35–40 percent are Protestant, independent or Pentecostal in some form;
• about 10–12 percent are Orthodox (Eastern and Oriental);
• a small remainder belong to other groups.

Pentecostal and charismatic Christians, across all these families, may number around 600 million (see Pentecostals and Charismatics).

The world's Christians today, by tradition (approximate)

Secular Europe

In Western Europe, the old heartland of Christendom, the story since the 1960s has been dramatic decline. Church attendance in countries like Britain, France, the Netherlands and Scandinavia fell to around 5–10 percent of the population or less. Many churches have been turned into apartments, bars or bookshops. Large numbers of Europeans now describe themselves as having no religion. Many others remain nominal members of state churches, "belonging without believing," or quietly believe without attending, "believing without belonging," in the British sociologist Grace Davie's phrase.

Historians debate why. Some point to long-term secularization driven by science, education, prosperity and the welfare state. Others, like Callum Brown, stress a sudden cultural revolution in the 1960s, especially changes in women's lives, since women had been the backbone of church life. Others point to the churches' own failures, or note that Europe is the exception rather than the rule, since religion is thriving in much of the world.

Yet European Christianity is not dead. Immigrant churches, African, Latin American, Eastern European and Asian, have brought new life to European cities. The fire that badly damaged Notre-Dame de Paris in 2019, and the worldwide emotion it caused, showed how much Christian heritage still means even to secular Europeans. The cathedral reopened in December 2024.

America: polarization and the "nones"

The United States long seemed the great exception: rich, modern and religious. But since the 1990s, the share of Americans with no religious affiliation, the "nones," has risen rapidly, from under 10 percent to around 25–30 percent. Mainline Protestant churches (Methodist, Presbyterian, Episcopal, Lutheran) have shrunk dramatically. Catholicism has been sustained largely by Latino immigrants. Evangelical churches held up better, but they too have begun to decline. Many observers link this to the close association of white evangelicalism with partisan politics. Meanwhile non-denominational megachurches, often charismatic in style, have grown. Thoughtful urban pastors like Tim Keller in New York tried to commend the faith to skeptical, secular audiences.

The abuse crisis

No issue has damaged the churches' credibility more than the sexual abuse of children and vulnerable adults by clergy, and its cover-up by church leaders. In 2002 the Boston Globe revealed that Catholic church leaders in Boston had for decades moved abusive priests from parish to parish. Similar revelations followed in Ireland, Australia, Germany, Chile, France, the US and elsewhere. Independent inquiries found thousands of victims. A French report in 2021 estimated over 200,000 minors abused by clergy since 1950. Protestant churches, including the Church of England and the Southern Baptist Convention, faced their own scandals.

The crisis led to resignations, enormous financial settlements, new safeguarding rules, and a collapse of trust, especially in once deeply Catholic countries like Ireland. Popes Benedict XVI (Joseph Ratzinger) and Francis met victims and introduced reforms, but many survivors felt the responses were slow and inadequate. MacCulloch, writing about the late 20th century, sees the abuse scandals as part of a broader crisis of clerical authority [check].

Sex, gender and division

Since the 1960s, questions of sexuality and gender have become the most divisive issues in many churches, often splitting denominations internally more deeply than the old divisions between them:

• Women's ordination: Many Protestant churches ordain women as ministers, and some as bishops. The Church of England ordained its first women priests in 1994 and women bishops from 2015. The Catholic and Orthodox churches do not ordain women as priests, and many evangelical and Pentecostal churches also restrict senior roles to men, though Pentecostals had women preachers from the start.
• Homosexuality and same-sex marriage: The consecration of an openly gay bishop in the US Episcopal Church in 2003 split the worldwide Anglican Communion. Global South Anglican churches, especially in Africa, strongly opposed it, and some formed alternative networks. Archbishop Rowan Williams struggled to hold the Communion together. In 2019–2024 the United Methodist Church effectively split over the issue, with about a quarter of its US congregations leaving. The Catholic Church's position remains traditional, though Pope Francis's 2023 permission for informal blessings of same-sex couples caused global controversy, especially in Africa.
• Abortion and bioethics remain central concerns, especially for Catholics and evangelicals.

These disputes often line up with geography. Churches in Western countries tend to be more liberal, and churches in the Global South more conservative. So the southward shift of Christianity has major consequences for these debates.

Persecution and martyrdom

Christians are today, by many measures, among the most widely persecuted religious groups in the world. Monitoring organizations report severe pressure in countries like North Korea, Afghanistan, Somalia, Nigeria, Pakistan, Iran, Eritrea, India and China. In Iraq and Syria, the ancient Christian communities of the Middle East were devastated by war and by the so-called Islamic State (2014–2017). Iraq's Christian population fell from over a million to perhaps a fifth of that. In Nigeria and the Sahel, jihadist groups have killed thousands of Christians, as well as many Muslims. The ancient churches of the Middle East, survivors of almost two thousand years, face the possibility of disappearing from the lands where Christianity began.

Other frontiers

• Interfaith relations: Christians increasingly live alongside people of other faiths. Dialogue with Jews (since Nostra Aetate) and with Muslims has become a priority, as in Pope Francis's 2019 "Document on Human Fraternity" signed with the Grand Imam of Al-Azhar.
• Creation care: Christians of many traditions, led by Ecumenical Patriarch Bartholomew I (the "Green Patriarch") and Pope Francis's Laudato Si' (2015), have made environmental stewardship a major concern.
• War and nationalism: The Russian invasion of Ukraine (2022), supported by the Moscow Patriarchate, showed again how Christianity can be harnessed to nationalism. It also deepened the split between Moscow and Constantinople over the independence of the Orthodox Church of Ukraine (2018–19).
• Technology: Streaming services during the COVID-19 pandemic (2020–22), online churches, and artificial intelligence raise new questions about community, worship and what it means to be human.

Major Christian movements of the 20th and 21st centuries

Looking back, looking ahead

In 2025 Christians marked the 1,700th anniversary of the Council of Nicaea, whose creed is still shared by most of the world's Christians (see Arius and the Council of Nicaea). It was a reminder of how much of this long history remains alive. The same year brought the death of Pope Francis and the election of Leo XIV, the first pope from the United States.

MacCulloch titled his book The First Three Thousand Years, hinting that there may be many more to come. He ends his history by suggesting that Christianity has always been remarkably adaptable and unpredictable, and that its future is open [check]. Shelley, writing as a believer, ends with confidence that the church, which has survived persecution, corruption, schism and secularism before, will continue because its life depends ultimately on God, not on human institutions [check].

What seems likely is that the Christianity of the 21st century will be:

• more Southern: African, Latin American and Asian;
• more Pentecostal and charismatic in style;
• more of a minority in many places, including its old European heartland;
• more diverse, with old divisions softening and new ones emerging;
• and, as always, deeply contested, as every generation argues anew about what it means to follow Jesus of Nazareth.