It does make sense when you consider their fundamental views and values

In their eyes, the only thing that truly matters is your relationship with god. They feel pre-marital sex is a sin harmful to that

Something like lifelong complications of STDs is nothing compared to that. Even if you died of AIDS as long as you’re going to heaven, it’s a better outcome than a long, happy life (to them)

I can understand their perspective when they truly believe it. The part I can’t wrap my head around is genuinely believing the religion

I’m supposed to believe there is an all-powerful god that made everything, and he personally cares what I do with my penis? He made everything in the universe, told us about it because he wants us to worship him, but also doesn’t want to prove he exists and will torment us for eternity for not believing in him. If true that would require unbelievable levels of narcissism