Accepting Christ doesn't just redeem us from our past, it actually puts to death the old person and replaces it with an entirely new one. As the Apostle Paul said in 2 Corinthians 5: "If anyone is in Christ, he is a new creation. The old has gone, and the new has come." So not only are we washed clean of our sins, we are made totally new creatures who have never had a sinful life in the first place.