You can’t lose when you turn to God. … The way to fight lust is to feed faith with the precious and magnificent promise that the pure in heart will see, face to face, the all-satisfying God of glory.
The challenge before us … is not merely to do what God says because He is God, but to desire what God says because He is glorious. The challenge is not merely to pursue righteousness, but to prefer righteousness. The challenge is to get up in the morning and prayerfully meditate on the Scriptures until we experience “joy and peace in believing” the “precious and magnificent promises” of God (Romans 15:13; 2 Peter 1:4). As faith in future grace satisfies us with the joy set before us, the biblical demand for purity of heart will not be burdensome (1 John 5:3), and the power of lust will be broken. Its deceitful compensation will appear too brief and too shallow to lure us in. – John Piper, Future Grace