the percentage of american consumers who regularly attend a church, mosque, synagogue or temple is lower than at any point in history, and continues to fall year-by-year. right now, what is the fastest growing religious affiliation inside the united states? the percentage of american consumers who regularly attend a church, mosque, synagogue or temple is lower than at any point in history, and continues to fall year-by-year. right now, what is the fastest growing religious affiliation inside the united states? catholic evangelical protestant buddhist muslim no religious affiliation