Religion is anti-humanist
Something I’m sure we’ve all noticed in organized religion, is the idea of abstinence, abstinence before marriage, intercourse for procreation only, or just plain guilt associated with sexuality.
Why do we do this? The answer, actually, is quite simple. It’s baked right into our DNA and psychology.
The “Good”:
Buddhists, Catholics, and other religious sects practice self-denial (even self-injury) in the effort to “connect” themselves to their God. Human nature and basic psychology dictate that we are unable (or unwilling) to subject ourselves to stories of suffering, strife, or peril of our deities unless we too, can share the burden of self sacrifice.
The Bad:
People are human, that is to say, that we are imperfect by design.

Where there is no way, we will find one. We don’t even need to get into the Catholic priests (again) to discover that Christianity’s view of sex is slanted. But even seemingly “strict” religions, like Islam for example, where followers (who are almost always “fundamentalists”) are willing to “die a thousand deaths” to be holy has excellent examples of good-old human behavior.
“To deny our own impulses, is to deny the very thing that makes us human.”
- Andy and Larry Wachowski
The irony here is that our very nature of existence causes both the inability to be abstinent, and the self-edification to crave it.