The practice of presenting an offering to the Lord reveals that no one can approach a holy God without a substitutionary animal to make atonement. Blood is a graphic representation of life. Due to the nature of human sin, atonement had to be made in exchange for any worshipper to draw near to God.
2 “Speak to the people of Israel and say to them, When any one of you brings an offering to the LORD, you shall bring your offering of livestock from the herd or from the flock.