God presented Christ as a sacrifice of atonement, through the shedding of his blood — to be received by faith. (Romans 3:25)
Quite simply, our English word, “atonement,” is the joining together of two words: “at onement.” It is essentially about reconciliation, restoring oneness where there has been estrangement. Theologically, there are two words that have been used to talk about the atonement we have with God through the blood of Jesus the Messiah. The first is propitiation, which is about appeasing and averting the wrath of God. The second is expiation, which is about removing the sin or offense.
The words used for “atonement” in the Bible are the Hebrew word kippur and the Greek hilaskomai (and its related forms). You might recognize kippur from the Jewish holy day, Yom Kippur, “Day of Atonement.” The Septuagint version of the Old Testament translates kippur as hilaskomai. Kippur generally has to do with covering, cleansing or the removal of sin (expiation), although there are a few instances of interpersonal relationships where it may have the sense of appeasement (propitiation). The sacrifices related to atonement are about expiation, purification, sanctification or dedication. The “mercy seat” in Leviticus 16:2 is the place of atonement. The Hebrew word there is kapporeth, from the word kippur. The Septuagint translates it as hilasterion, from the word hilaskomai.
Let us look now at how Paul speaks of the “sacrifice of atonement” in Romans 3:25. “God presented Christ as a sacrifice of atonement.” The Greek word translated by the NIV as “sacrifice of atonement” is hilastarion, the word used in the Septuagint for “mercy seat,” the place of atonement. There are a few English versions, including Young’s Literal Translation and the Lexham English Bible, that translate it that way in Romans 3:25.
Several English versions translate it — wrongly, I think — as “propitiation.” This make no sense, for this reason: It was God himself who offered Jesus as the atoning sacrifice. If it were propitiatory, seeking to avert the wrath of God, then we should have to suppose that God was trying to appease himself — as if he were at odds with himself and needed to be reconciled to himself. But the fact that it was God himself who offered the sacrifice of atonement indicates that God was already graciously and mercifully disposed toward us. It was because “God so loved the world,” not because God was so angry at the world, “that he gave his one and only Son” (John 3:16).
This was not an act of retribution but an act of mercy. It was not an offering God made because he needed to be appeased but an offering he made because he already wanted to be gracious to us. God was not trying to gain God’s own good will toward sinful humanity but the cross was the manifestation of God’s good will toward sinful humanity. God was not reconciling himself to us, turning himself back toward us — for he had never turned away from us. Rather, in offering Jesus as the “sacrifice of atonement,” God was turning us back toward him, that we may be at one with him.