"Your diet is too spicy; try eating bland foods and maybe you'll masturbate less, SINNER!"

https://piefed.social/c/historymemes/p/1978410/your-diet-is-too-spicy-try-eating-bland-foods-and-maybe-you-ll-masturbate-less-sinner

Was John Kellogg also the one who convinced Americans that male circumcision was somehow medically necessary, again as an effort to cut down on masturbation? I think I’ve heard that before.
Yep. He also tried to convince people to destroy the nerve endings on a girls clitoris with acid to avoid, in his words, “abnormal excitement”
Why are religious people so against sex?

Potentially schismogenisis at least in the Christian and Muslim traditions. Middle Eastern and European pagans had more comfort with sex. Ultimately this has resulted in a lot of sexual liberation movements coming with rejection of religion. Though you do occasionally get Christians who are super into free love and consider it a part of Christianity.

That said, this is just a guess. I strongly suspect that individuals who are deeply ashamed of their sexual desires or lack thereof latch on to prudish relitions as a justification to try to fix people having sexual desires.

I think it originates from ancient social constructs. Because its very easy for men to knock up women and then abandon them and their child, it became necessary to have social rules to ‘bind’ couples through marriage. And strongly forbid sex outside marriage or adultery. In biblical times, adultery was such a severe crime it was often a death sentence.

These days contraceptives are so widely available it makes zero sense. But it made some sense in early civilizations thousands of years ago when infantcide was a very common practice.

That makes a lot of sense until you look at the evidence. In the epic of Gilgamesh, Shamhat, a sacred prostitute, has sex with Enkidu for a week before introducing him to civilization and then dipping out of his life. We have evidence of varied attitudes on sex at a cultural level around the world. In fact in the middle East we have such a clear picture of a sexually open culture that it’s a relevant question how the attitudes we see in the bible come up so close to Babylon. David Graeber argues that it’s related to the adoption of money in his book Debt, but I really feel that the schismogenetic component is more worth using for the short internet comment level explanation.
Shamhat - Wikipedia