In this video, Dr. Joel Kim explains the difference between justification and sanctification.
One of the teachings of Scripture that we ought to cherish, but often forget, has been the teachings on justification and sanctification. And for those of us who love history and have studied history, the recovery and precision of understanding of justification and sanctification during the time of the Reformation is a cherished heritage for us, as we continue to dive into the Word and understand better what the Lord is doing in our lives. So, what are justification and sanctification, and how do they differ? Perhaps this can be a class by itself, and many books have been written regarding it, but maybe I can summarize it this way, by borrowing the words of the confessions in particular. I’m from the PCA, so I use the Westminster Shorter Catechism as a way to teach people. And the Westminster Shorter Catechism asks, “What is justification?” And it begins by simply saying that it’s an “act of God.”
And in particular, it emphasizes it’s an act of God’s free grace, wherein our sins are forgiven—He forgives us of our sins. And then He goes on to point out and accepts us as righteous in His sight only because of the righteousness of Christ Jesus imputed, counted to us, and received by faith. What’s intriguing about sanctification as a whole is that it talks about the work of God’s free grace—the same Catechism understands—and it talks about the fact that we continue to grow in our understanding of the image of God. That is, we are renewed in order that we may reflect the image of God. That we may have strength enabled to die to our sin on a regular basis so that we may live unto righteousness, is how the Catechism language differentiates the two.
Perhaps I can define it this way or at least explain it this way. Here, both are teachings of Scripture that deal with our sinfulness. But justification is the way God forensically, that is, legally, declares us righteous before His sight. Here, we have offended God in an eternal way. Here justification in Christ Jesus allows us to stand in a new position because of the declaration of God, the judge—who also, by the way, has come to our aid as our Mediator. Whereas sanctification deals with our sin in such a way where the pollution and corruption of sin that we have continues to be corrected by the workings of God through the Spirit in our lives. Perhaps in seeing the difference in the ways that it deals with sin, the additional understanding we ought to have in mind is that justification is once and for all—a declaration forensically that cannot be overturned. For it’s done, not because of what we have done, but it’s about what Christ has accomplished in His life and on the cross. And it’s a once and for all declaration.
This is why the Confession uses the word an “act” of God’s free grace. Whereas sanctification is a lifelong process of change, renewal, and growth by the workings of God. We are not saved by grace alone and then sanctified by our works. No, grace is through and through at work here, for God is the one who justifies and sanctifies us. But in sanctification, it’s a lifelong journey of becoming more like Christ Jesus, dying to our sins, and living unto the righteousness that God has declared for us.
So here, in our understanding of justification and sanctification, they cannot be separated. They go hand in hand. It deals with us in our sinful condition, as God desired in Christ Jesus, but it also cannot be reversed in terms of their order, because it’s not because of our sanctification that we’re justified. We are justified by Christ Jesus and therefore start a lifelong process of progressive change in us to reflect His image.