When Christians become obsessed with their sins those sins are elevated to the level of idols. We fear sin more than we trust God. We agonize over our sins and in effect, punish ourselves for our sins when that punishment has already been taken by Another. We set out on a quest to overthrow those idols of sin...and we set out with the wrong weapons. Our weapons are too often "carnal" and not "mighty in God" (II Cor.10:3-6). We take law into battle and not grace. The weapons of law are useless and indeed harmful in the hands of sinful men. We are weighed down in battle by our own weapons.
The law leads to bondage; grace leads to victory.
Jesus Christ did not come to destroy the law but to fulfill it (Mt.5:17), and fulfill it He did. The law was fulfilled in and by Jesus, and then nailed to the tree in this Fulfillment. The literal embodiment of the fulfilled law was nailed to Calvary. This is precisely why the Lord fulfilled it. Not to impress folk with His spirituality nor to set forth the perfect example. But He fulfilled it in order to fulfill it in perfect obedience to the Father as the Substitute, the perfect and final Sacrifice.
The incarnation of the law fulfilled was nailed to the cross. The Lamb of God was nailed to the cross. "The way, the truth, and the life" was nailed to the cross. The "door," the "Good Shepherd," "the bread of life," "the living water," "the light of the world," "the resurrection and the life," "the true vine," were nailed to the cross in Jesus Christ. Our justification, sanctification, reconciliation, glorification, righteousness and wisdom were nailed to the cross in Jesus Christ. And thus He said from the cross, "It is finished." And the Resurrection guarantees our possession of these blessings by our union with Christ in His resurrection.
This is the weapon we take into battle against spiritual forces in high places...and temptation...and sins commited; the finished work of Christ on the cross. Armed with truth and grace we overcome our obsession with our sins, an obsession that magnifies our sins and gives them reign over us and weakens us. The more we grow in grace and knowledge of what Christ finished in our stead, the more freedom and joy we will find in this present life. And conversely, the more we attempt to overcome sin in our own futile way, the stronger becomes the temptation and the more we sin. Grace is the Holy Spirit putting to death the deeds of the body (Rom.8:13).
Grace says to us "it is finished," law says "you must finish it." The law promises us victory over sin (as we perceive the law) but leads only to defeat. Grace points us to Calvary and gives us victory in Christ over the strength of sin, the law. The more we know of grace the more we are moved toward holiness in thankful obedience to His gracious work of love and grace in our sinful hearts. The more we know of grace the greater our joy and liberty. The more we know of grace the greater our desire and ability to turn from sin and to put to death what is earthly in us, living in a manner pleasing unto Him. It can be done...by grace alone.
To grow in grace and knowledge of the finished work of Jesus Christ is to be the delight of every believer who truly seeks the "how" of putting to death what is eartly in each of us.