Sex Is a Pointer to, Not a Substitute for, God.
Sexuality is designed by God as a way to know God in Christ more fully; and that knowing God in Christ more fully is designed as a way of guarding and guiding our sexuality. Or to put it negatively: all misuses of our sexuality distort the true knowledge of Christ; and all misuses of our sexuality derive from not having the true knowledge of Christ.
Aus: John Piper. Justin Taylor. Sex and the Supremacy of Christ. Crossway Books: Wheaton 2005.