Does the new creation still have a sin nature or not? This seems to be a divisive theological problem.
In 2 Cor. 5:17 Paul wrote that if we’re in Christ, we’re a new creation, the old has gone and the new has come. This statement is in the past perfect tense, meaning it has already happened and is complete. But he also wrote that try as he might he couldn’t completely stop sinning. Then he said that when we sin God doesn’t consider us to be the guilty party, but attributes our behavior to the sin nature that still lives within us (Romans 7:18-20).
From a comparison of these two statements we can conclude that when we’re born again all the sins of our life are forgiven, even those still in our future. All charges against us have been dropped and our record has been expunged. Colossians 2:13-14 confirms this. And from that point on God, who sees the end from the beginning, chooses to see us only in our perfected state, a new creation free from sin. In Ephesians 2:6-7 Paul wrote that God already sees us seated with Christ in the heavenly realm.
So here’s the bottom line. Being subject to the constraints of time we know we still have a sin nature, but being outside of time God sees us as being pure and holy, as righteous as He is (2 Cor. 5:21). He no longer considers our sin nature to be part of us.