Identity in Christ

I have been crucified with Christ. It is no longer I who live, but Christ who lives in me.
Galatians 2:20

All very well, we repented of our sin, which is obvious we all have, but how do we keep from sinning again? Is that even possible?
Yes and no…
The bible says no man is good but God. To a degree bad men can still do good things btw, but at it’s core we are sinful and even our good deeds are stained with wrong motiations, pride and selfishness.
So our core nature is corrupt, our very essence.
How then do we live holy lives? How do we submit to the will of God and not continue to put ourselves above God and others?
There is only one way we can do that. When we repent and start believing in God our sins are not only forgiven but He changes us from the inside. He gives us a new heart.
Jesus Christ (his spirit) himself lives now inside of us and because of that we are able to surrender to God and live according to his will and standard.
God does not fix our old sinful nature. Rather He reckons it to have been killed when Jesus was killed on the cross. Because that is what we deserved. So Jesus died in our place and now sees us as having paid the penalty for our sin, which is death.

He does not leave us death though. Just as Jesus rose from the death and He looked totally different after that, so in a sense we are raised from the death and we are now a totally new person. The bible even calles it born again. So we now have the perfect nature of Jesus, because as the bible says our spirit is now united with His spirit. And rather than God becoming defiled by us the opposite happens: we are made pure because of our unity with The One that is pure, God himself.
So we don’t have to anxiously strive to start living holy in our own strength all of a sudden and walk on our toes for the rest of our lives. Instead God gave us a new heart, a new spirit that is perfect and good. The only thing it takes to conform our behaviour to that new nature we now have inside is to lean on God. To trust that He indeed is now our righteousness. That we are holy and can live holy because He is holy and we are one with Him.
It can take time to learn this and we might be working on doing this to an increasing degree our whole lives. The christian live is a journey that we walk with God and the more we spend time with Him the more we become like him in our daily living. Our spirit is now saved and made perfect but we still have to surrender our soul (mind, will and emotions) and body to this spirit because we still have sinhabits so our mind needs to be renewed by the truth of who we are now and who God is for us daily.
But we don’t have to do this on our own. He guides us in doing this and we get to do this together with other believers so we can encourage eachother and be reminded of the truth every day.