Bible memorization is always time well spent. Whether you're tackling extended sections, or "fighter verses" for specific sins, or passages particularly helpful in pastoral ministry, surely all Scripture memory is "profitable for teaching, for reproof, for correction, and for training in righteousness" (2 Timothy 3:16). And especially useful are one-verse statements of the gospel.
When you memorize a "gospel verse," and keep it warm, you have hidden in your heart a divinely inspired and inerrant expression, in human language, of the very point of the whole Bible and all of history. You carry with you the sword of the Spirit in its strongest alloy. One-sentence encapsulations of the Bible's central message strengthen our spiritual backbone and solidify our core, rooting us deep down in the bedrock of God’s heart and the nature of the world he made, and sending us into confident combat with unbelief, whether our own or someone’s else. "Gospel verses" are invaluable in both evangelism and discipleship.
[Read the rest of the article at Desiring God.]