This decline has not been a steady one. Indeed, over the last 20 years, church attendance has fallen by 20 percent. This might not sound like cause for concern off the bat. And if you're not a person of faith, you might rightly wonder why you would care about such a thing.

Church attendance is simply a measure of something deeper: social cohesion. It's worth noting that the religions with the highest rate of attendance according to Pew Forum have almost notoriously high levels of social cohesion: Latter-Day Saints, Jehovah's Witnesses, Evangelical Protestants, Mormons and historically black churches top the list.

There's also the question of religious donations. Religious giving has declined by 50 percent since 1990, according to a 2016 article in the New York Times. This means people who previously used religious services to make ends meet now either have to go without or receive funding from the government. This, in turn, strengthens the central power of the state.