Such is the confidence that we have through Christ toward God. Not that we are sufficient in ourselves to claim anything as coming from us, but our sufficiency is from God, who has made us sufficient to be ministers of a new covenant, not of the letter but of the Spirit. For the letter kills, but the Spirit gives life. – 2 Corinthians 3:4-6 ESV
Paul knew what it was like to attempt to live up to God's standards. Of his own admission, he had been a poster-boy for adherence to the Mosaic law. “I was circumcised when I was eight days old. I am a pure-blooded citizen of Israel and a member of the tribe of Benjamin—a real Hebrew if there ever was one! I was a member of the Pharisees, who demand the strictest obedience to the Jewish law. I was so zealous that I harshly persecuted the church. And as for righteousness, I obeyed the law without fault” (Philippians 3:5-6 NLT). He had the pedigree and the religious resume to prove that he had been a loyal, law-abiding, God-fearing Jew who had done everything in his power to keep God happy and earn his way into His good favor. But now, after having come to faith in Christ, Paul knew that adherence to the law was a dead-end street that would never lead anyone to a right relationship with God. Referring to the law, he says point blank, “the letter kills”. He had learned that it was the Spirit who made possible life in Christ and a restored relationship with God. Paul had seen the changes made in the lives of the believers in Corinth – written on human hearts by the Spirit of the living God (2 Corinthians 3:3). The remarkable transformation of their lives, made possible by their faith in Christ and the Spirit's presence in their lives, was all the proof Paul needed. God had done for them what the law could never have accomplished. “The law of Moses was unable to save us because of the weakness of our sinful nature. So God did what the law could not do. He sent his own Son in a body like the bodies we sinners have. And in that body God declared an end to sin's control over us by giving his Son as a sacrifice for our sins” (Romans 8:3 NLT).
According to Paul, our new life in Christ is made possible by the Spirit who lives within us. It is not based on human effort any more than our salvation was. He had to reprimand the Galatian believers about this very thing. “How foolish can you be? After starting your Christian lives in the Spirit, why are you now trying to become perfect by your own human effort?” (Galatians 3:3 NLT). Life in Christ is never accomplished in the flesh. It is the work of the Spirit. It is our faith in Christ and our dependence upon the Spirit that makes possible our ongoing transformation. Any attempt at self-righteousness on our part will not end well. Self-sanctification is impossible. It is the work of God accomplished through the power of His indwelling Spirit. It is the difference between our sinful, natural self and our new, Spirit-directed nature.
In his earlier letter to the believers in Corinth, Paul raised the important distinction between our old nature and our new nature in Christ. “Thus it is written, ‘The first man Adam became a living being’; the last Adam became a life-giving spirit. But it is not the spiritual that is first but the natural, and then the spiritual. The first man was from the earth, a man of dust; the second man is from heaven. As was the man of dust, so also are those who are of the dust, and as is the man of heaven, so also are those who are of heaven. Just as we have borne the image of the man of dust, we shall also bear the image of the man of heaven” (1 Corinthians 15:45-49 ESV). We are new creations. We are spiritual creatures who have a spiritual destiny. We are no longer of this world. We are children of God who bear the likeness of His Son. We have within us the very Spirit of God. His divine DNA now flows within us, giving us spiritual life and vitality. Yes, we still have human bodies that are slowly decaying and dying. We still struggle with the presence of our sin natures. But Paul reminds us that the Spirit gives life – new life. We are capable of living righteously and rightly. We are no longer slaves to sin and left to struggle through life attempting to earn our way into God's good graces. Jesus, the last Adam, became a life-giving spirit. He gave His life so that we might have new life. He sent the Spirit to live in us so that we might live like Him. We have a new capacity to live obediently and faithfully that we never had before. That's why Paul can so confidently state, “I have been crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me. I do not nullify the grace of God, for if righteousness were through the law, then Christ died for no purpose” (Galatians 2:20-21 ESV). Our righteousness is not based on our human effort. It is based on faith in the Son of God and a reliance on the Spirit of God. “By his divine power, God has given us everything we need for living a godly life. We have received all of this by coming to know him, the one who called us to himself by means of his marvelous glory and excellence” (2 Peter 1:3 NLT). We have all that we need to live the life we have been called to live. We have salvation through Christ. We have sanctification through the Spirit. God has done and is doing all that is necessary to accomplish His will in our lives. And all that we are required to bring to the table is our faith.