Leviticus 7:11 And this is the law of the sacrifice of peace offerings, which he shall offer unto the LORD.
God has made peace with man now, but even back in the Old Testament, it was God that came looking for man. It was God who came to Abraham in the beginning. It was God who gave them a tabernacle where He would dwell with them. God then prescribed offerings and sacrifices that could be offered. These would atone for sin and make peace with God. Every offering was important, and the way it was offered was very important. God was showing us the coming of the Lord Jesus. Jesus is the true peace offering. Jesus is the sacrifice that makes atonement. Each offering was a picture of Jesus dying for us. It was important that they learn how to show this picture correctly. As you read the Old Testament realize that it all points to Jesus!