2 Corinthians 5:17
Therefore if anyone is in Christ, he is a new creature; the old things passed away; behold, new things have come.
What am I most thankful for?
That the Creator of the universe would look upon sinful man and make a way for us to be reconciled to Him.
That He sent His own Son to be born of a virgin, live a sinless life, suffer the agony of death on a cross, and rise again on the third day so that all who repent and put their trust in him will be saved.
I'm thankful that He softened my hard heart and granted me repentance, and that He continues His good work in me, all for His own glory.
I'm thankful that though man may remember my sinful past I know that God looks on me and sees Christ's righteousness.
Therefore there is now no condemnation for those who are in Christ Jesus.