David Masci

Only three Roman Catholics have ever run for president on a major party ticket, and all were Democrats. But that may be about to change. So far six Catholics (including some early favorites) are running for the 2016 Republican presidential nomination.

Some legal scholars and others are trying to determine how a ruling granting same-sex couples a constitutional right to wed might affect religious institutions.

Popes have written encyclicals on an array of topics, ranging from the nature of work to the virginity of Jesus’ mother, Mary.

Fact Tank sat down with David Campbell, a professor of political science at the University of Notre Dame, to explore what the new findings mean.

One big reason evangelical Protestants have not declined at the same rate as other major Christian groups is that they are gaining new converts at a greater rate than they are losing people who were raised in the tradition.

The number of Christians in Europe is forecast to drop by about 100 million by 2050, while the share of Muslims and smaller religious minorities will increase.

Demographer Conrad Hackett explains how he and his team put together our major new report and why it differs from past efforts to predict religious change.

The share of the world's Christians in Europe will continue to decline while the percentage in sub-Saharan Africa will increase dramatically.

Seven-in-ten Americans rate him favorably, including two-thirds of those with no religious affiliation, a Pew Research Center poll finds.