I don't understand, why do Christians not like Masturbation or porn

[Chad32]

If you take one of the most basic instincts of man and mark it as a disease (sin), for which you hold the cure (belief in your brand of god), it makes selling your products a lot easier, doesn't it? especially when your entire selling point rests on the inherent guilt of people?

This, probably more than anything, though the story of Onan does give some simblance of justification. It's the same thing as saying thoughts are as bad as actions. Anything to make you think you're inherently evil, and constantly in need of repentance.

Some believe sex should only be for procreation between married couples, so anything that deviates from that is bad. Masturbation, contraception, and abortion. Even sex education, which a proven way to reduce STDs, unwanted pregnancy, abortion, divorce, and pretty much any problem related to sex these people can come up with. They don't understand that teens and young adults are going to have sex, so you might as well make it safe sex. It's like telling a kid not to use a seatbelt when they drive.