Let's get this first thing straightened out: the title isn't literal, it's metaphorical. Just think, without religion the world would be much better. No disputes over the "right" thing to believe. That means no wars over religion. We'd have more money because we wouldn't have to donate, build churches, etc. We'd have an overall better outlook on life because our consciouses wouldn't be so powerful.
Okay, I'll put it into different terms. God created all this stuff for our species' sake, correct? Well, God created women for men and men for women. In the link, it also states that men and women were to have two reasons for intercourse. a) For reproduction and b) for intimacy, or, "fun." By having sex with another man/woman you are being ungrateful to God. That is why it's a sin. Understand? If you don't, just say you don't to avoid future confusion.
If you're confused, take a deeper, longer look at the link. Plus I explained it. >__>
No, I get it, I just think it's a few chickens short of a chicken coop. The link says that god made man and women for each other, and he only sanctions the togetherness of a man and a woman as a husband/wife...but then it kind of "jumps" to if you don't do that, and instead have homosexual sex, that that's a sin and is wrong. HOWEVER, it does NOT GIVE A REASON FOR THIS. It keeps circling back to "God says it's wrong" There is no reason.
