While some churches may have trouble filling their pews, the appeal of megachurches continues to grow. The Hartford Institute for Religion Research (HIRR) defines megachurches as Protestant Christian congregations with a sustained average weekly attendance of 2,000 or more people, including children, at its worship services, at all its worship locations.

In its most recent study, HIRR has found more differences between megachurches and other congregations beyond size. Megachurch survey respondents were more likely to describe their worship services as inspirational, joyful, thought-provoking, and innovative than those who belonged to other congregations. A more contemporary form of worship in many megachurches includes “praise bands,” consisting of electric guitars, bass, drums, and keyboards, along with the use of technology such as projections, large screens, and more.

Other megachurch characteristics include youthful, racially diverse congregations; significant involvement in missions and global and community outreach; and a choice of small-group activities.

Many of these churches are located in very devout regions of the country. Here are the most religious states in the nation. And, click here to see the most religious county in each state.

Many of the 25 largest megachurches in the U.S. listed here had humble beginnings, often starting out in the homes of the founders and moving into rented spaces before burgeoning into multi-campus congregations that attract thousands of weekly worshippers. And according to HIRR, the growth continues, with more congregations reaching megachurch status each year.

To determine the 25 largest churches in America, 24/7 Tempo used data on average weekly attendance by congregation, originally compiled by the Hartford Institute for Religion Research (HIRR). A megachurch is defined as having regular weekly attendance of at least 2,000 people. Denominations came from a list of 65 denominations provided by HIRR. Names of pastors and church locations also came from HIRR. HIRR research is updated regularly and attempts to reflect the most current conditions.

Click here to see the 25 most popular churches in America