Religion in the United States

Religion in the United States is both widespread and diverse, with higher reported levels of belief than other wealthy Western nations. Polls indicate that an overwhelming majority of Americans believe in a higher power (2021), engage in spiritual practices (2022), and consider themselves religious or spiritual (2017).

Christianity is the most widely professed religion, with the majority of Americans being Evangelicals, Mainline Protestants, or Catholics, although its dominance has declined in recent decades, and as of 2012 Protestants no longer formed a majority in the US. The United States has the largest Christian and Protestant population in the world. Judaism is the second-largest religion in the US, practiced by 2% of the population, followed by Hinduism, Buddhism, and Islam, each with 1% of the population. States vary in religiosity from Mississippi, where 63% of adults self-describe as very religious, to New Hampshire where 20% do. The elected legislators of Congress overwhelmingly identify as religious and Christian; with few exceptions, both the Republican and Democratic parties nominate those who are. Religious figures (Carrie Nation, William Jennings Bryan, Martin Luther King Jr., Wallace Fard Muhammad, Jimmy Carter, Jerry Falwell, Abraham Joshua Heschel), have played a significant role in American politics.

Among the historical and social characteristics of the United States that some scholars of religion credit for the country's high level of religiousness include its Constitutional guarantees of freedom of religion and legal tradition of separation of church and state; the early immigration of religious dissenters from Northwestern Europe (Anglicans, Quakers, Mennonites, and other mainline Protestants); the religious revivalism of the first (1730s and 1740s), and second (1790s and 1840s) Great Awakenings, which led to an enormous growth in Christian congregations—from 10% of Americans being members before the Awakenings, to 80% belonging after.

The aftermath led to what historian Martin Marty calls the "Evangelical Empire", a period in which evangelicals dominated US cultural institutions. They influenced measures to abolish slavery, further women's rights, enact prohibition, and reform education and criminal justice. New Protestant denominations were formed (Adventism, Jehovah's Witnesses, the Latter Day Saint movement (Mormonism), Churches of Christ and Church of Christ, Scientist, Unitarian and Universalist, Pentecostalism). Outside of Protestantism, an unprecedented number of Catholic and Jewish immigrants arrived in the United States during the immigrant waves of the mid to late 19th and 20th century.

Social scientists have noted that beginning in the early 1990s, the percentage of Americans professing no religious affiliation began to rise from 6% in 1991 to 29% in 2021—with younger people having higher rates of unaffiliation. Similarly, polling indicated a decline in church attendance, and the number of people agreeing with the statement that religion is "very important" in their lives. Explanations for this trend include lack of trust in numerous institutions, backlash against the religious right in the 1980s, sexual abuse scandals in established religions, the end of the Cold War (and its connection of religiosity with patriotism), and the September 11 attacks (by religious Jihadists). Many of the "Nones", those without a religious affiliation, have belief in a god or higher power and spiritual forces beyond the natural world. As of 2024, Christianity's decline may have leveled off or slowed, according to the Pew Research Center, though according to the Public Religion Research Institute it has continued to decline.