To kill an innocent animal seems quite cruel. Our modern sensibilities are often by this requirement. But the lesson is this: Sin is serious! It offends a holy God. Human behavior bears consequences for all of creation. God gave human beings life so that they might worship, serve, and honor Him. When Adam and Eve perverted this gift by rebelling against God, they cut themselves off from the very source of life. They “died” (spiritual separation from God, see Genesis 3), a condition that would have persisted enacted to fix the problem. The penalty for sin is death, yet God made it possible under Old Testament law for animals to substitute for people. By giving one life, another could be saved. But this system was instituted only as a short-term arrangement.
At the right time, God sent Jesus Christ, often called “the Lamb of God,” to be sacrificed on a Roman cross as final payment for all sins for all time. Jesus, the perfect substitute, rendered the Old Testament sacrificial system obsolete. Now people can be forgiven and experience spiritual life and union with God, not by killing innocent animals, but by trusting in the crucified Christ as their substitute.
LEVITICUS 4:15- And the elders of the congregation shall lay their hands upon the head of the bullock before the LORD: and the bullock will be killed before the LORD.