This coming Sunday, I'll be preaching on Romans 6:12-23. While doing some research, I pulled out my copy of Karl Barth's The Epistle to the Romans and found this wonderful passage:
“Grace is the power of obedience; it is theory and practice, conception and birth; it is the indicative which carries with it a categorical imperative; it is the call, the command, the order, which cannot be disobeyed. Grace has the force of a downright conclusion; it is knowledge which requires no act of will to translate it into action, as though the will were a second factor side by side with knowledge. Grace is knowledge of the will of God, and as such it is the willing of the will of God. Grace is the power of the Resurrection: the knowledge that men are begotten of God, that it moves and rests in Him, and that it is beyond all concrete things, beyond the being and course of this world. Inasmuch as men have discovered it, Grace is the existence begotten of God, the new man, created and redeemed by God, the man who is righteous before Him and in whom He is well pleased, the man in whom God again discovers Himself, as a father discovers himself in his child. Of supreme importance, then, is the demand that I, the new man in the power of the resurrection and within the krisis of the transition from death to life, should by faith and under grace—will the will of God. As the man under grace, I am in a position to hear and understand this demand, for existentially and assuredly I live from God and am what He desires. By this demand, moreover, I am reminded of that primal Origin by which my existence is affirmed, and I perceive that I—and yet not I—am” (207–208).