Hebrews 4:11-12

So then we must be eager to experience this faith-rest life, so that no one falls short by following the same pattern of doubt and unbelief. For we have the living Word of God, which is full of energy, like a two-mouthed sword. It will even penetrate to the very core of our being where soul and spirit, bone and marrow meet! It interprets and reveals the true thoughts and secret motives of our hearts.