For though we walk in the flesh, we do not war after the flesh: (For the weapons of our warfare are not carnal, but mighty through God to the pulling down of strong holds;) Casting down imaginations, and every high thing that exalteth itself against the knowledge of God, and bringing into captivity every thought to the obedience of Christ. II Corinthians 10:3-5
It is indisputable that every born again child of God, and every faithful preacher of the gospel of God's free grace in Christ, has a God given desire to honor the Lord with their lives. Truly, it is God that works in them, causing them to will and to do of His good pleasure. They genuinely loathe their sin. Never do we excuse sin or suggest in any way that disobedience is of minor importance. If, however, I preach in such a way as to draw the attention of my hearers to look at their works to get assurance of their salvation, I have caused them to look away from the very source of their obedience. I have brought them under the bondage of the law, for the law is the only standard by which they can measure their success. I have armed them with carnal weapons to fight a spiritual warfare. They are doomed to failure.
If I emphasize “their obedience” as the grand and final goal of the gospel, I have, in so doing,
de-emphasized the “obedience of Christ” as the glorious end of all things. I have made the salvation of a sinner a mere stepping stone to the greater end, their obedience. Looking to my obedience as proof of salvation is no different than looking at it for the cause of my salvation. If you want me to obey God, tell me about Christ. Tell me about His accomplished work of redemption. Tell me about His love for me. Tell me about the Father's satisfaction with Him. Tell me about His fulfilling the whole law for me. Tell me about His intercession for me. Tell me about my acceptance before God in Him. Tell me about how His shed blood completely covers all my sin. Tell me about His power to save to the uttermost those who come to God by Him. Point me to Calvary. Please don't send me back to Sinai. I will either be crushed by its impossible demands, or I will pretend before men and lie to myself, exposing my self-righteousness before God. Your attempt to make me holy will only cause me to be guilty of the worse sin of all.