Who said anything about that, Lucia? I sure didn't. I don't care if young people have sex, it's their lives and their bodies and if they want to, well, who am I to stop them? Go for it, but don't come up to me and blame me for giving you permission. As the Travis Tritt song says, "Here's a quarter, call someone who cares."
As for the "religious people," as you say. Churches have taught sex is dirty, the human body is dirty, politics is dirty. Perhaps if pastors taught their people that holy sex is wonderful and unholy sex isn't (where the std's come in from, as do the reasons for abortions); if parents that don't attend church would teach their kids properly there wouldn't be any problems, either. As for the politics, well, :topic: and I won't go there = beating a dead horse.
For the sex, parents aren't ashamed to have it, why should they be ashamed to explain it to their kids using proper names? They don't need to turn it into an object lesson, just talk about it when the kids want to talk about it, answering their questions truthfully, frankly and without becoming jell-o. There's way more to puberty than sex and the growth of body hair, I sure hope parents understand that. While they're at it, there's more to sex than just the feeling of "hey, you turn me on!" Sheesh!!