The first three offerings in Leviticus portray the God-ward side of the Cross. The remaining two (sin and restitution) foreshadow the human side of the Cross. You have noted the refrain “be forgiven” (4; 20, 26, 31, 35; 5: 10, 13, 16, 18; 6: 7). Men and women are consciously and appropriately concerned with forgiveness. The sin and restitution offerings are closely related. Both offerings are for unintentional sins. No offering was available for intentional sins. Defiant sins brought death not forgiveness (Num. 15: 30 – 31). David understood this when he committed adultery and conspired to have a man murdered. He, as King, could have offered thousands of sacrifices but they would not have been righteous sacrifices (Ps. 51: 19). David knew he had to fall on the mercy of God (Ps. 51: 1). The sin and restitution offerings were for those who inadvertently violated God’s law. David knew about that as well and so he prayed, Cleanse me from my hidden faults (Ps. 19: 12). Essentially the sin offering covered a violation of the Law without deliberate intent while the restitution offering dealt with individual sins affecting people and property for which restitution could be made. The first three offerings were voluntary but the sin and restitution offerings were mandatory. They were mandatory because everyone sinned.
Sometimes the people sinned representatively. That is why God began the list of sin offerings with the High Priest. When this leader sinned it was serious as illustrated in the fact that his offering was the same as that offered when the entire nation sinned. Failure in leadership is huge and God wanted His leader to be transparent and openly confess his sin.
Sometimes the people sinned collectively. The entire nation might fail to comply with some aspect of the Law and the elders acting in behalf of the people would bring an offering before the Lord. Even today our entire nation bears corporate guilt for bloody sins like abortion.
Sometimes the people sinned individually. It might be a leader or a common person but sin was often committed by the Israelites and an offering needed to be brought to acknowledge it.
Bringing an offering meant the person acknowledged his or her sin. They were renouncing it and the burning of the sacrifice outside the camp (4: 12, 21) meant the removal of the sin. Our Lord was therefore crucified outside the city (Heb. 13: 10 – 16). The restitution offering carried the extra requirement that the person or persons injured be satisfied by the offending party. One of the ways we know we are serious about dealing with our sin is if we get serious about repaying others.
There is great news for the Christian: In Him we have redemption through His blood, the forgiveness of our trespasses (Eph. 1: 7). Even our willful sins are now under the blood of Christ!