“Both justification and sanctification are by faith, but whereas faith is the instrument through which we receive the righteousness of Christ, faith is the root and principle out of which and sanctification grows (XVII.i.19). We say that justification is by faith alone, because we want to safeguard justification from any notion of striving or working.”

Over the last few weeks, there have been a number of posts in the Reformed blogosphere related to sanctification and good works. I won’t attempt to survey all the relevant posts, but the main ones include:

• John Piper’s Foreword to Tom Schreiner’s new book where Piper notes in passing that though we are justified by faith alone, there are conditions for our final glorification such that we do not “attain” heaven by faith alone.
• Mark Jones scanning the history of Reformed dogmatics and writing in support of Piper.
• Rick Phillips reminding us that “James, Is, You Know, In the Bible.”
• And R. Scott Clark sounding a contrary note with more than a dozen related posts, including ones on attaining heaven through faith alone, conditions in the covenant of grace, and whether Hebrews 12:4 teaches sanctification by works.

I’m not going to attempt to sift through all the arguments in these posts. Readers familiar with my writings can (rightly) guess that I am sympathetic to the points John, Mark, and Rick are making (though I also appreciate what Scott wants to guard against and am grateful for his attention to the careful language of older Reformed sources). But instead of engaging in a point-counterpoint I thought it might be helpful to take a step back and look at five questions about sanctification and good works. The five questions (and answers) are distilled from Francis Turretin’s Institute of Elenctic Theology. It’s amazing not only how careful Turretin was with his distinctions, but also how relevant his discussions are for our own day.

Throughout this week I will be walking through the five questions Turretin tackles in his chapter on “Sanctification and Good Works” (Seventeenth Topic). Here are the five questions, slightly modified for ease of understanding:

1. How does sanctification differ from justification?
2. Can we fulfill the law absolutely in this life?
3. Are good works necessary to salvation?
4. Can justified believers do that which is truly good?
5. Do good works merit eternal life?

First up, how does sanctification differ from justification?

Turretin makes clear that he is not talking about sanctification as a broad term describing the Christian’s position as set apart for God. Rather, he is talking about sanctification in the narrow sense usually assumed by theologians: namely, the renovation of man by which God takes the in-Christ, justified believer and transforms him more and more into the divine image (XVII.i.2-3). Importantly, Turretin argues that sanctification can be understood “passively,” inasmuch as the transforming work “is wrought by God in us,” and also “actively,” inasmuch as sanctification “ought to be done by us, God performing this work in us and by us” (XVII.i.3). This is a crucial point. Sanctification is not understood correctly if we do not understand that God is doing the work in us, but at the same time we are also working. Any theology that ignores either the active or passive dimension of sanctification is getting it wrong.

Justification and sanctification must not be confused. The most serious, and potentially damning errors, surface when the two are not carefully distinguished. So how do justification and sanctification differ?

• They differ with regard to their object. Justification is concerned with guilt; sanctification with pollution.
• They differ as to their form. Justification is a judicial and forensic act whereby our sins are forgiven and the righteousness of Christ is imputed to us. Sanctification is a moral act whereby righteousness is infused to the believer and our internal renovation is affected.
• They differ as to the recipient subject. In justification, man is given a new objective status based on God’s acquittal. In sanctification, we are subjectively renewed by God.
• They differ as to degrees. Justification is given in this life fully, without any possible increase. Sanctification is begun in this life but only made perfect in the next. The declaration of justification is once for all. The inward work of sanctification takes place by degrees.
• They differ as to the order. God only sanctifies those who are already reconciled and justified by faith. (XVII.i.10)

There has been a lot of discussion about whether sanctification is by faith alone. I’ve argued before that “sanctification by faith alone” is not the best phrase to use, not least of all because it can lead to confusion about the absolutely essential affirmation that “justification is by faith alone.” There is a sense in which “sanctification by faith alone” can be a true statement. Is sanctification is a gift that only comes to those who put their faith in Christ? Yes and Amen. But the “by” in “justification by faith alone” is not the same as the “by” in “sanctification by faith alone.” Both justification and sanctification are by faith, but whereas faith is the instrument through which we receive the righteousness of Christ, faith is the root and principle out of which and sanctification grows (XVII.i.19). We say that justification is by faith alone, because we want to safeguard justification from any notion of striving or working. But sanctification explicitly includes these co-operations (XV.v.1-2), making the description of “alone” misleading at best and inaccurate at worst.

Kevin DeYoung has been the Senior Pastor at University Reformed Church in East Lansing, Michigan since 2004. Kevin blogs at the Gospel Coalition; this article is used with his permission.