I'm going to disagree with PVC's take on this. *surprise*

@Husar: God did not make people to spend all day praying, and they aren't commanded to by scripture either. Rather, it says that all aspects of our lives, whether just everyday things like work or even sex, should be sanctified unto the Lord. If they are to be sanctified, they must be done in their proper order, and in the case of sex this means only within marriage. Marriage in Christianity is not some artibrary rule we follow for the sake of discipline or something, it is a creation ordinance rooted in the earliest stories of Genesis. A monogamous relationship between one mand and one woman is part of the natural/inherent nature of mankind, therefore anything else is unnatural and a rebellion agaist God's order.

Sure people will say what about evolution, monogamy is unnatural, spread your seed etc, but I am talking about from a Christian (more specifically, biblical) perspective.