Through expiation—the work of Christ on the cross for us—the sin of all those who would ever believe in Christ was canceled. 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. (gotquestions.org)