Praying to God is the most important thing a believer can do. The Weapon of Prayer is a sword that slays the devil. Introduction and conclusion by best selling author Glenn Langohr. E.M. Bounds expounds on God’s need of people who pray. He explains: Why prayer moves God to act, how doing God’s work needs prayer first, how the early apostles gave themselves to prayer, why effective preaching depends on effective praying, and why we need to intercede for others.