This insightful principle by the reformer Martin Luther means: "Simultaneously righteous, and a sinner." That is, a genuine believer in Jesus is simultaneously: 1. RIGHTEOUS (justus) in the sight of God through faith in Christ, having received His imputed righteousness. This is our identity in Christ. "For we maintain that a man is justified by faith, apart from observing the law." Romans 3:28 "However, to the man who does not work but trusts God who justifies the wicked, his faith is credited as righteousness." Romans 4:5 "Therefore, there is now no condemnation for those who are in Christ Jesus." Romans 8:1 2. A SINNER (peccator) in his own sinful flesh, which remains unchanged even after conversion. "I know that nothing good lives in me, that is, in my flesh. For I have the desire to do what is good, but I cannot carry it out. For what I do is not the good I want to do; no, the evil I do not want to do--this I keep on doing." Romans 7:18-19 "For the flesh desires what is contrary to the Spirit, and the Spirit what is contrary to the flesh. They are in conflict with each other, so that you do not do what you want." Galatians 5:17 Hence every believer daily experiences the constant battle between the flesh and the spirit--the new spiritual nature in Christ. Though we are genuinely converted, our sinful flesh remains with us until we receive our resurrection bodies. "He will transform our lowly bodies, so that they will be like His glorious body!" Philippians 3:21 "Simultaneously righteous, and a sinner." What I am in Christ: RIGHTEOUS. What I am in my flesh: SINNER. In justification, God credits Christ's perfect righteousness to our account, while our sinf