The moralist tends to see sex as dirty or at least a dangerous impulse that leads constantly to sin. There will be an approach-avoidance relationship with sex. The uneasy conscience of the moralist will lead to either complete avoidance OR to a very driven, breathless need for sexual experience. Both come from a glory-vacuum within, which makes sex into a way to fill the emptiness. On the other hand, the hedonist sees sex as merely biological and physical appetite. Thus the hedonist may be less convoluted and troubled about sex, yet they have also given up on the deep longing of their heart to have union with someone sexually that is completely, unconditionally, and permanently true to them.
But the gospel shows us that sexuality is to reflect the self-giving of Christ. He gave himself completely without conditions. So we are not to seek intimacy sexually but then hold back control of our lives. If we give ourselves sexually we are to give ourselves legally, socially, personally – utterly. Sex is only to happen in a totally committed, permanent relationship of marriage. Through Christ’s transformation of us, that ideal is somewhat realizable even between two sinners.
– Tim Keller