God’s uses His word to help us examine our hearts and to see if we are right with Him. His word will cut us to pieces in order to put us back together in a way that is pleasing to Him. If we are not reading the word regularly we cannot see the areas in our lives that God wants to change. Some people are cut to the heart and respond in a right way and others get mad and want to ignore God’s warnings. Are you reading His word daily so that you might know how to live and so that it can let you know the areas where you need to let God work?
God examines our innermost attitudes and motives. The “scalpel” He uses is His Word. The Word of God is “living” because it is the word of the living God (3:12), and it is “active” (energetic, powerful). Constable
“What the author is saying is that God’s Word can reach to the innermost recesses of our being. We must not think that we can bluff our way out of anything, for there are no secrets hidden from God. We cannot keep our thoughts to ourselves. Morris, p. 44.
Hebrews 4:12 For the word of God is living and active and sharper than any two-edged sword, and piercing as far as the division of soul and spirit, of both joints and marrow, and able to judge the thoughts and intentions of the heart.