One of the cardinal rules of American politics is that if you want to gain high office, you have to express religious beliefs. If you are not a believer or are lukewarm, then you have to fake it. Some fakers are better than others at conveying sincerity but it does not really seem to matter even if you are a pretty obvious phony. All that the religious base cares about is that you pay lip service to the Christian god. If you also push for the policies that the religious right favors (anti-abortion, anti-contraception, anti-LGBT, and anti-sex), then it does not matter even if you do not go to church regularly or mangle your religious references.
Donald Trump is of course a prime example of this. He is a blatant phony when it comes to being religious and is not even good at acting like he is sincere. Seth Meyers looks at Trump’s religion.