Faith to Faith

When God justifies a sinner, it does not mean that the man was actually good. It does not even mean, at that point, that He makes him good. It means that God treats the sinner as if he had not been a sinner at all. It is also the righteousness of Jesus Christ accredited to our account. It's more than just the forgiveness of our sins. That would merely leave us with a blank slate. Innocence is not perfection, and so we need more than His death, we need His life. Just as our sin was imputed to Christ so that He could pay the full price of it for us; in exactly that same way, His perfect life counts as ours by imputation – 2 Corinthians 5:21 / Romans 3:21-22, 4:5-6 / Philippians 3:9 / Galatians 3:24-29 / Colossians 3:3 / Jeremiah 23:6. We are not justified by the righteousness Christ works in us, but by the righteousness Christ is for us.