Republican presidential candidate Ben Carson speaks at a North Texas Presidential Forum hosted by Faith & Freedom Coalition and Prestonwood Baptist Church last weekend. Brandon Wade/AP hide caption

toggle caption Brandon Wade/AP

Evangelical Christians hold their hands out in prayer during the annual March for Jesus in downtown Rio de Janeiro, Brazil, in 2013. Evangelicals play an increasingly large role in the nation's politics. Victor R. Caivano/AP hide caption

toggle caption Victor R. Caivano/AP

Republican presidential candidate Mitt Romney pauses during a visit to St. Paul's Lutheran Church while campaigning in Berlin, N.H., on Dec. 22. Charles Krupa/AP hide caption

toggle caption Charles Krupa/AP