God’s Principles Are Nails; His Word Is the Hammer
Have you ever watched a little boy learning to use a hammer? The lad grasps the hammer near the head of the shaft and is merely able to go "tap, tap, tap," hardly working the nail into the wood. He has the right tool but no power.
Compare the craftsman carpenter as he holds his hammer down at the bottom of the shaft gaining all the leverage he can. His arm goes "bam, bam, bam," driving nails home using a few swift hard strokes without damaging the surface of the wood. He holds the tool to get the power.