“He shall lay his hand on the head of the burnt offering, and it shall be accepted for him to make atonement for him. Then he shall kill the bull before the LORD, and Aaron’s sons the priests shall bring the blood and throw the blood against the sides of the altar that is at the entrance of the tent of meeting.” Leviticus 1:4-5
By laying a hand on the head of the blameless sacrifice, the offerer established a relationship with the animal such that it was accepted on the offerer’s behalf. This meant that the offerer received the benefits of the sacrifice, such as atonement.
In general, the word atonement communicates two ideas: (1) ransoming, and (2) purifying. On the one hand, sin or impurity puts people at risk of the Lord’s judgment, from which they need to be ransomed. On the other hand, sin and impurity are defiling, as a result of which people need to be purified. The word atonement has both of these in view: it is a “ransom-purification” taking place by means of the animal’s lifeblood.
Jesus was the ultimate blameless sacrifice presented on our behalf (1 Peter 1:19), and those who put their trust in him receive all the benefits of his sacrifice, including forgiveness of sin and adoption into God’s family (Romans 4:25–5:2; Galatians 4:4–5; 1 John 1:7). Because Jesus’ sacrifice is atoning, it is sometimes described as that which ransoms us (Matthew 20:28) and at other times as that which purifies us (Titus 2:14). In either case, we can receive this atonement because Jesus has given his lifeblood in place of our own (Romans 5:8; 1 Pet. 3:18). This is such a precious gift, given at such a great cost, it fills us with thankful reverence and a desire to live lives worthy of our Savior (1 Corinthians 6:18–20; 1 Peter 1:17–19).
Original Post: Crossway