In my opinion Donald Trump is absolutely not “religious.” He is not even “spiritual.” He is a totally amoral narcissist.
Trump’s choice as White House “spiritual advisor” (Paula White) and the many established televangelists who support him do not give him … “Christian counsel.” They are just sick venal fakers who speak gibberish and hope to make money “preaching.” Most reasonable Americans, both religious and irreligious, write off these fruitcakes and opportunists for the frauds that they are.
I agree that Trump is not a religious or spiritual person. I think most evangelicals would agree.
BUt their political alliance with Trump is not built on the idea that he is "one of them" but that he is not their enemy, like Hillary and Biden are, and is willing to work with them, like Liberals are not.
That is completely normal and reasonable.
Liberals are pretending it is not, because a populist allying with the evangelicals, is a force that could threaten their agenda, so they start the trash talking.