"Even if our happiness is likely to be increased by keeping sex within marriage, this is the wrong question to ask. A Christian apologetic for marriage is settling for second best if it says to people, “Join us and live our way because you’ll probably be happier that way (and have better sex into the bargain).” They may or may not be happier in the shallow sense of having better sex. They may have no sex at all: Jesus didn’t. Instead, what Christians say to people is, “Learn that the glory and honor of God is far more important than your personal satisfaction and the fulfilment of your longings and desires. And learn to center your life on his glory and purposes so that nothing so fills your heart with joy as seeing his purposes fulfilled. Then you will have the deepest personal satisfaction and joy in the world, as you rejoice in the glory of God.” This is the most radical de-centering of human beings imaginable. But we must do this if we are to make sense of sex. Christopher Ash.
From here. (A continuation of this discussion.)