[SillyEvee]

Well, I'm not much of one for an intermediate between me and G-d (as Matt put it), but not all organized religions are like that.
I agree that often, people use parts of their religious texts out of context to hurt others, but that's the fault of the people, not the scripture, right? And a lot of the people who use scripture to discriminate or incite hate aren't mainstream. They're a small but very vocal (and/or militant) offshoot of their religion. Yeah, it sucks that they're so loud, but I don't think they're very representative of organized religion as a whole. What about Quakers? The Society of Friends...what's more peaceful than that? And Quakers are pretty organized, eh?
I think the theory behind "telling people how to live their lives," at least in Judeo-Christian religions is that G-d gave people the Bible, which tells them how to live. Since they belive that G-d is perfect, He must know better how to live life, right? So if you really want to live a good life, you should follow the instructions in the Bible. That's my understanding of that belief anyway. So, according to the Judeo-Chrisitan view, you should abstain from sex before marriage NOT for your sake or because you're not ready for sex but precisely BECAUSE that's what G-d says is best for you.
I'm not saying to have to believe that, but it is remarkably consistent with the rest of Judeo-Christian beliefs about G-d: that He's perfect, that He's the ONLY being that is, that He really does want what's best for you. I don't think it's to be controlling in a manipulative way. I think it's just because the people preaching believe that's what's really in your best interest.