I was asked this question today and thought I would share my answer.
“Reading the Hebrews 10:1-4 section which clearly states that animal sacrifice could not remove sin. This surprised me. I went back to Leviticus 4 where it says in several verses after the priest lays hands on, kills the animal, and sprinkles the blood, the persons sin will be forgiven. Can you help me understand this seeming incongruity? Thank you!!“
Thank you for your thoughtful email. It really shows that you truly value God’s Word. Volumes have been written on this topic, but the short answer is that, if we believe Hebrews is just as much God’s word as Leviticus, then God has revealed something new to us about the Old Testament sacrifices that wasn’t revealed in Leviticus. Certainly God was forgiving sins after these sacrifices took place. That is plain from reading Leviticus. However, there may also be multiple layers as to what forgiveness means in Leviticus. If it meant temporary cover from God’s wrath on earth, e.g. not having a chasm open up from the ground and swallow you (Numbers 16), that is certainly part of the picture. But is that kind of forgiveness eternal forgiveness? What we learn after God the Son walked the earth is that the power of forgiveness for eternal life was never in the blood of those animals. Sacrifices were a shadow and copy of the real thing: Jesus’ death on the cross. Forgiveness for eternal life was always, as it is today, by God’s grace and made possible through the planned shedding of the blood of Jesus, which was the plan before from the foundation of the world (Acts 4:28, Revelation 13:8, 17:8). Sacrifices were an act of obedience, but that obedience may or may not have been the fruit of faith in God. Just as Abraham was saved by his faith (Romans 4, Genesis 15:6), God forgave sin back then just as He does today, by grace through faith, because atonement would be made by Jesus on the cross for it.
Jesus said Abraham had faith in Christ: “Your father Abraham rejoiced that he would see My day. He saw it and was glad.” (John 8:56).
God’s Word in Hebrews says Moses had faith in Christ: “[Moses] considered the reproach of Christ greater wealth than the treasures of Egypt.” (Hebrews 11:26).
Jesus sent his apostle Jude to write to us that it was even Jesus who saved people from out of Egypt: “…Jesus, who saved a people out of the land of Egypt…” (Jude 5)
So, eternal forgiveness has always been by faith in Christ. I hope this answer helps! Let me know if you have any questions or comments.