Just because the brilliant Commander in Chief promises victory on the beaches doesn’t mean the troops can throw their weapons overboard. The promise of victory assumes valor in battle. When God promises that his church will be kept from defeat, his purpose is not that we lay down our sword and go to lunch, but that we pick up the sword of the Spirit and look confidently to God for the strength to fight and win. Wherever the promised security of God is used to justify going AWOL, we may suspect there is a traitor in the ranks.
—John Piper