Question: "What is expiation?"
Answer: The word “expiation” does not appear in the New Testament, but it does accurately describe an aspect of the sacrifice of Christ on our behalf. Expiation means “to cover sin” and/or “to cleanse sin.” Expiation reflects the idea that the negative and degrading effects of our sin are removed through the grace of God. Another word for expiation is atonement, and truly this is one of the results of Jesus’ atoning death for us.
Through expiation—the work of Christ on the cross for us—the sin of all those who would ever believe in Christ was cancelled. That cancellation is eternal in its consequence, even though sin is still present in the temporal sense. In other words, believers are delivered from the penalty and power of sin, but not the presence of it. Justification is the term for being delivered from the penalty of sin. This is a one-time act wherein the sinner is justified and made holy and righteous in the eyes of God who exchanged our sinful natures for the righteousness of Christ at the cross (2 Corinthians 5:21). Sanctification is the ongoing process whereby believers are delivered from the power of sin in their lives and are enabled by the new nature to resist and turn away from it. Glorification is when we are removed from the very presence of sin, which will only occur once we leave this world and are in heaven. All these processes—justification, sanctification and glorification—are made possible through the expiation or cancellation of sin.
It is good to know also that there are other benefits of Jesus’ death for us. One of them, not included in the concept of expiation, but just as true and biblical, is propitiation, which is “to appease wrath.” Truly the atoning death of God the Son satisfies the wrath of God the Father against rebellious, sinful humanity (John 3:36; Romans 5:9). Expiation, justification, sanctification, glorification, propitiation, and many more - we have countless reasons to praise God and to run to Him in faith and trust.