Why Memorize Scripture?

Memorizing Scripture enables me to hit the devil in the face with a force he cannot resist, to protect myself and my family from his assaults. What are you hitting him with? He is millions of times stronger than you, and he hates you, and your family, and your marriage, and this church and God. How anybody walks through this [devil-infested] world without a sword in his hand is beyond me.

—John Piper