Tho its elites were churchier, early America was less churchy than today. It also was drunker, gambled & patronized prostitutes more, had abortions, more corruption, more dangerous, plus slavery, sweat shops, child labor, sex exploitation...hardly nirvana. Thankful for today.
AND YET-- in 1831, all church bodies collectively could probably only claim about 22% of the population as members.
Now, some of this is gimmicky: enslaved people were often not counted as members. Traditions vary on counting children, as well as to a lesser extent women.