Because sexual desire is one of the most powerful forces in human life, and the world is very busy exploiting the power of that desire for its own godless purposes. God has something to say about this desire which he created in our bodies. And we need to hear it—loud and clear.
For those of us who believe God is wise and good, the real tragedy about the world’s view of sex is that it destroys the greatest joy of sexual relations and ruins lots of lives as well. The thing that would grieve me most, if my sons ever committed fornication, would not be what they got wrongly, but the future they threw away. The gain of sinful pleasure is never worth the loss of holy joy.
The great tragedy of sin is the good we miss, not the evil we attain.
The best reason for chastity is that it will make us unimaginably happier. We must persuade our teenagers and young adults not to sell their birthright for a single bowl of pottage.
– John Piper