It depends for me, I wouldn’t have any issue simply dating a practicing Christian but an absolute red line for me would be hypothetical children getting exposed to ideas like original sin. Genetically I already carry a bit of a tendency for batshit ideological insanity, if I ever have kids it will be my duty as a father to make sure they get a head start on dealing with that which means giving them the tools to see ideas like original sin as a potential source of psychological harm; if there’s a chance of them being like me then they’ll require a psychological foundation of pretty much the polar opposite to conservative Christianity to be mentally healthy.

I’d sooner not have kids at all than tell them they’re broken, they’re unclean, they’re sinners etc which I think will present far more problems than dating ever would and I’m guessing most Christians will want to have kids at some point leading to something of an impasse. I don’t think most Christians would understand what I’m trying to do, that I’m trying to make sure a cycle of horrible ideology and horrible mental health ends with me. I don’t think the god of my childhood is a true god at all; I think it’s a self-perpetuating neuropsychological phenomenon that evolved during the English Reformation and is subject to the same selection pressure everything else is, it’s nothing more than a collection of ideas people keep having. It would be a rare Christian who heard that and still wanted to date me.