A person can give their heart to the Lord, the Lord can clean the human heart. God will accept a person when the human being want to follow God's way.
We need to have a loving fear of the Lord because we all deserve God's judgement. But he offer mercy to mankind. The cross of Jesus fulfills the Old Testament sacrifice system. The animal sacrifice is a credit card because the sacrifice forgives one sin but the cross of Jesus can forgive every sinful activity.
I am thankful for the cross of Jesus. I don't have to sacrifice animals. The Messiah forgive my sinful activity so there is forgiveness.