I’m an “evangelical” who has no problem with Trump on this issue. He stated that such issues should be left to the states; he is correct, given that the only Constitutional function of the federal government is to provide for national defense against foreign enemies.
I am not thrilled about the Pence selection because of what you said, but it is possible Trump knows something about Pence that we don’t. Trump has to worry about his VP being behind an assassination attempt; since he seems to want a politician as his VP, he is aware that 95% of the politicians want him dead.