Who says? This type of stereotype shows just how ingrained Christianity is with Republicanism. According to some religions, all I have to do is love Jesus to get into heaven. According to others I need to bomb and kill people. I'm not saying those two things are on the same level, but it just goes to show that there's no agreement on what gets you into heaven.
If we're talking about Christianity, most Democrat policies are more in line with Jesus than Republican policies. I feel like a lot of "religious" people are only religious in the sense that they condemn gay people. I know I'm going to get some heat in the comments for this entire article, but if you're not a racist or homophobic Republican, good. I'm not talking about you, but get your people right.