The punishment for sin was death. Yet how could God kill man who was made in His image and likeness. Man made in God's image was a disgrace to Him, yet God loved mankind deeply. I think that God was therefore extending mercy to us by allowing animals to be sacrificed in place of us as a sign that through the shedding of an innocent's blood , sins were forgiven. However, animal sacrifices could never adequately atone for human sin. Only a human made in God's image and likeness could really atone for human sins. Hence Jesus, the unblemished one, had to come to fulfil this atonement and cleanse humanity. Through Jesus' faithfulness, He was able to redeem all of humanity so that we can now be called children of God through our faith in Him. Praise be to God for His loving kindness and compassion for us.