Believers who have been born again (regenerated) should have the desire to be conformed to Christ completely and should mourn when we find out that there are sins STILL to repent during the walk in the Spirit, which indicates that God (Holy Spirit) has not yet finished His work in us. In the Reformed tradition, this is the stage of sanctification within the whole plan of salvation, i.e. ordo salutis, so roughly:
regeneration + justification (past) -> sanctification (present) -> glorification (future)
(see a sample rough description here).
Much ink has been spilled, words said, and even fights conducted over the imputed vs. imparted vs. infused righteousness in connection with the justification stage in the Catholic vs. Protestant debate, described roughly here, and after 500 years it's very clear where each side stands and at the end of the day, it's mainly over using different terminologies to talk about roughly the same thing. This question is NOT about justification, and NOT about righteousness at all, but about our progressive conformity with the image of Christ.
In Catholicism, the map of this sanctification journey is very explicitly laid out, relatively stable, rich, and fine-grained through the teaching of venial vs. mortal sins, virtues, sacrament of reconciliation, merit, stages of holiness and examples from the saints, how God's grace interact with our will, purgative vs. illuminative vs. unitive ways, state of grace vs. state of mortal sin, what happens when we die before the sanctification work is finished (purgatory), etc. In other words, believers have a lot of concepts and tools at their disposal to track their progress, although the more saintly one becomes the larger the remaining distance one will feel to finish it, similar to how the more we know the more we feel we don't know.
But in the Reformed tradition, it seems that believers do not have as many tools nor even a reliable standard to "track our progress" as we are being transformed into the image of Christ during the sanctification stage. What should we use as a measure? Is it our sorrow over sin or our likelihood to sin? Is it tangible growth in the fruit of the spirit? Is there such a thing as sanctity? Does sanctity become the "real" property of the believer (even though it's in cooperation with the work of the Holy Spirit producing fruits in us)? Is it synergistic or monergistic? Does it even make sense to talk about "progress" similar to how in the Catholic scheme believers are becoming progressively holy? What is holiness vs. righteousness, same or different within the human person? How is it related to measurable character / virtue improvement? I hesitate to use the term "infused", but yet considering how it is the Holy Spirit at work, can we say that during sanctification we receive the infusion of grace that truly makes us more holy?
Another way to pose the question is in terms of the gap between unfinished sanctification and the beginning of glorification when we die. How would it feel, the jump between our 10%, 20%, 50%, or 90% sanctified state to 100%? Is it like everyone now has the same brand new car whether the old car has many accidents / 30 year old vs. cosmetic blemishes? In contrast, in the Catholic scheme, the feeling would be more of continuity.
A third way of asking the question is this: can a Reformed believer uses the concepts / map and the tools / practices of the Catholics? There is only one image of Christ for both traditions, one Holy Spirit that gives us grace, and one believer who is being sanctified. So why not use the same concepts/tools such as the theory of virtues, spiritual exercises, discernment of sins, etc? I realize that it can horrify Catholics to see Reformed believers trying to make progress without Catholic sacraments, or conversely it can horrify a Calvinist in another way.
I have tried to make the question acceptable to the site, so with the above background, here's the only question to answer: In the Sanctification stage (Reformed perspective) are believers truly becoming more like Christ ("infusion" not imputed)? An answer should include a reference to a scholarly article / book describing the believer's subjective perspective in the Reformed scheme of sanctification (not just doctrines from God's point of view). Comparison with the Catholic scheme of "tracking progress" is a plus.
2018 blog article by Justin Dillehay, Baptist pastor with MDiv from Southern Baptist Theological Seminary, to set the stage and highlight the pastoral importance of this question: Two Pastoral Thoughts on Justification and Sanctification, includes a list of new books on Sanctification, Transformation, and Union with Christ.
Very promising 2017 book Sanctification by Dr. Michael Allen that can answer this question from Reformed tradition, from a new series New Studies in Dogmatics following the tradition of the venerable Studies in Dogmatics, reviewed in depth in 11(!) blog articles, and by a professor of Systematic Theology here. Quote from the latter review:
... the author roots the holiness of believers in the character of the God who saves them in Christ. In a time when many Christians associate the gospel more with benefits than with the Christ who brings benefits with him, this emphasis is needed desperately. The character of the holy triune God and the nature of union with Christ are some of the primary reasons why the gospel must ultimately include sanctification. It is only this line of thinking that removes the question as to why we should obey God if we are justified by faith alone in Christ alone. A man-centered gospel might be content with forgiveness without likeness to God. However, a God-centered gospel begins with forgiveness without being satisfied with anything less than perfection in holiness before the Lord in glory.
I have one minor quibble with this book in relation to the author’s appeal to John Owen on the habits of grace. While Allen rightly points to Owen’s insistence that the Spirit infuses habits of grace in believers through their union with Christ (250–51), he neglects Owen’s equal insistence that infused habits of grace are insufficient to produce actual holiness. Owen insisted that believers need continual acts of the Spirit in every act of obedience to God. This strengthens the relationship between sovereign grace and the human responsibility to pursue holiness. Later Allen adds that infused habits of grace do not detract from “ongoing acts” of grace (254), yet this still falls short of Owen’s robust emphasis on the continual and personal acts of the Spirit in the lives of believers. This minor adjustment would make a great book even better.
Brief, informal survey from different Reformed theologians (Calvin, Turretin, Brakel, Hodge, Bavinck, Berkhof): Is Sanctification Monergistic or Synergistic? A Reformed Survey
An essay summarizing 5 Protestant tradition on Sanctification based on a 1987 book by 5 different authors Five Views on Sanctification, along with the author's reaction on each concluded by his own view. The 5 views are:
- Wesleyan (Melvin Dieter)
- Reformed (Anthony Hoekema)
- Pentecostal (Stanley Horton)
- Keswick (Robertson McQuilkin)
- Augustinian-Dispensational (John Walvoord)
John Owen's Pneumatologia (1677–78) with relevant excerpts here: The Work of the Spirit in Renewing the Spiritual Life of Believers on holiness, supernatural habit, union with Christ, duties of the believer, etc.