Sanctification as Set Apart and Growing in Christ: A Review

Köstenberger, Marny. Sanctification as Set Apart and Growing in Christ. Short Studies in Biblical Theology 16. Wheaton: Crossway, 2023. 125pp excluding end matter.

Summary and Critique

Köstenberger reveals the thesis of Sanctification at the very end of chapter 7: “In Christ, believers are positionally sanctified through the gift of the indwelling Holy Spirit and empowered to work out their salvation in progressive sanctification, propelled toward moral excellence, missional community, and meaningful relationships. In Christ, they are assured of future perfect sanctification when glorified in his presence. In Christ, they desist from dead works and start living a new life—life in the Spirit” (124).

Unfortunately, I do not recommend Sanctification for the following reasons.

The thesis is unclear until the very final section of the final chapter.
The approach to the topic was inefficient and confusing. Köstenberger takes a New Testament book-by-book approach to sanctification instead of a thematic approach. Because of this, she is quite repetitive and it becomes difficult to follow her points. It would have been better if Köstenberger had organized the book with each chapter dedicated to a specific element of sanctification that worked toward a goal. For example, a chapter on positional sanctification, then a chapter on progressive sanctification, then a chapter on glorification.
Köstenberger’s treatment of sanctification in the Old Testament was pitiful with only 18 pages total. Köstenberger should have been upfront from the beginning that she was only going to treat the New Testament. Thus, this book failed in its goal of a biblical theology approach to sanctification because it neglected the Old Testament. Many books in this series take a salvation-historical approach to their topic, tracing the theme through salvation history. This would have been a great way to treat the topic of sanctification and one that would have made the treatment of the theme in the Old and New Testaments more meaningful. For example, the holiness/sanctification problems in the Old Testament are rectified and working toward a real goal in the New Testament.
Köstenberger was overly reliant on David Peterson’s book Possessed by God: A New Testament Theology of Sanctification and Holiness in the NSBT series. Köstenberger’s book Sanctification almost seems like a summary (or cliff notes) of Peterson’s book, making it surprising that this monograph got through the editorial phase of publishing. As such, I recommend Peterson’s book rather than Köstenberger’s book.

Summary of Each Chapter

Introduction

Köstenberger lists three reasons there is confusion about sanctification.

The Language Gap. Confusion is caused by the translation of ἁγιασμός, ἁγιωσύνη, ἁγιότης, and ἅγιος (2).
The Tradition Gap. There are multiple and contradictory perspectives on sanctification (2–3).
The Relevance Gap. Many people simply do not care about holiness (3).

Köstenberger’s method is to trace the concept of sanctification through Scripture to determine what it says “on its own terms and in its own original context” (4–5).

Chapter 1: Foundation—Creation and Covenant

This chapter is an extremely brief sketch of the theme of holiness in the Old Testament. Within the Old Testament, there is “a developing picture of the holiness of God and his expectation that his people live holy lives before him” (25).

Köstenberger summarizes the meaning of the holiness language in the Old Testament:

קוֹדֶשׁ (noun): “It typically designates a holy person, thing, place, or time, something sacred, consecrated to God” (8).
קָדוֹשׁ (adjective): “It conveys a sense of moving people into the divine realm” (9). “God, in his very essence, is holy and calls his people to be holy as well” (9).
קדשׁ (verb): The verb conveys the state of holiness or the transition toward holiness (i.e., consecration) (10). “Such consecration involves both entering into communion with the divine realm and being set apart from the worldly domain” (10).

Holiness in the Old Testament usually refers to “God’s desire for his creatures to be consecrated or devoted to him and thus fit to live in communion with him” (11).

Personally, I believe 18 pages (pgs 7–25) was not enough to treat the theme of holiness/sanctification in the entire Old Testament. Köstenberger’s writing is not as clear as it could be. This chapter seemed more like a summary of salvation history in the Old Testament with smatterings of sanctification littered throughout. I found myself struggling to figure out what she was trying to say about sanctification/holiness while she was summarizing the Old Testament.

Chapter 2: Inauguration—God’s Kingdom

Chapter 2 moves into the New Testament’s understanding of sanctification. Köstenberger begins this chapter with word studies on the terms related to sanctification.

ἅγιος (adjective). This is “the primary word translated ‘holy’” (28).
ἁγιάζω (verb). This verb means “‘to make holy,’ that is, ‘to sanctify’” (28). It includes both positional sanctification and progressive sanctification (29).
ἁγιασμός, ἁγιωσύνη, ἁγιότης (nouns). These nouns are typically translated “holiness” or “sanctification” (29). There is little to no difference in meaning between the three terms (29).
ἀρετή (noun). This term denotes “moral excellence, goodness, or virtue” (30).
ἅγιος (adjective). “The very identity of believers, the essence of those who are born again, is encapsulated in what they are called: ‘holy’” (30).
Τέλειος (adj)/τελειότης (noun). This term refers to either maturity or perfection (30). “The idea of perfection indicates the goal toward which believers are to strive in sanctification, the idea of attaining full maturity” (31).
πνευματικός (adjective). “The term spiritual is used in Scripture to describe the work of the Spirit in humanity, as the energizing source for the resulting maturity or growth in believers’ lives. In view of the fact that the Spirit is the primary agent of sanctification, it is crucial to learn about the Spirit’s role and work in the life of the believer” (31).

The rest of this chapter focuses on the Sermon on the Mount and the Gospel of John. Jesus’ teaching on the Sermon on the Mount (Matt 5–7) is Him instructing his followers how to live holy lives as the new holy people (33). Köstenberger focuses on having the right heart as a necessity of living the holy life as set forth in the Sermon on the Mount: “This heartfelt obedience—far exceeding mere external compliance—is central to kingdom living” (36).

The Gospel of John depicts Jesus’ body “as the new holy sanctuary, the new temple (John 2:18–21; 4:19–24)” (37). Köstenberger argues that Jesus’ followers are not just set apart to be holy, but they are set apart “so they can bear witness to the salvation wrought in Jesus to a lost and dying world” (45). Christians are set apart for missions in the same way Jesus was set apart for missions in his coming to earth to call a people unto himself.

Chapter 3: Sanctification—The Age of the Spirit

This chapter focuses on the books of Acts, James, Galatians, and Thessalonians.

The Early Church (Acts). “There is in Acts a strong missional component in sanctification” (50).
Jewish Christianity (James). A Christian is considered mature if he (1) remains steadfast while in the midst of trials (53) and (2) controls his tongue (54).
Walking in the Spirit (Galatians). In the New Covenant, the believer’s relationship with God “is sustained by the Spirit and no longer through animal sacrifices or law observance” (55). Further, life in Christ “is to be lived according to the Spirit, not by observing mere external stipulations” (55). To live according to the Spirit (or to “walk by the Spirit”) means we allow the Holy Spirit to influence and guide our actions, which results in maturation (57–58). “We will know that we are walking in the Spirit when we see the fruit of the Spirit exhibited in our lives and the deeds of the flesh begin to wane” (59).
Comprehensive Sanctification (Thessalonians). “The Spirit is active both at conversion and throughout believers’ lives (1 Thess. 1:5–6). He [Paul] stresses the vital importance of the Spirit in sanctification (1 Thess. 4:8; 5:23; 2 Thess. 2:13) and observes that believers are set apart from their pagan neighbors and empowered to witness to Christ. In addition, the Spirit enables believers to refrain from sexual immorality and other vices” (61). 1 Thessalonians 5:23–24 gives us four important pieces of information on sanctification (63):
- “God’s desire is for believers’ complete sanctification.”
- “The time at which this comprehensive sanctification will be complete is on judgment day.”
- “Sanctification is God’s work.”
- “Our ultimate and complete sanctification is an absolute certainty.”

Chapter 4: Community—United to Christ

This chapter focuses on the books of 1 & 2 Corinthians, Romans, and Ephesians to show the individual and corporate aspects of sanctification.

1 Corinthians. The believers in Corinth are already “sanctified,” meaning they are “set apart for Christ at conversion (positional sanctification)” (73). “On the basis of this sovereign act of God, Paul affirms that they are ‘called to be saints’: they are to become what they already are (progressive sanctification)” (73).
2 Corinthians. “Not only does the Spirit set people free; he also gives them life and transforms them from within” (76).
Romans 6–8. “The Christian life is to be lived apart from the law, based on the gracious gift of Christ in the power of the Spirit. Instead of struggling to live according to the written code, believers now have the Spirit living inside them to guide them and to produce fruit in keeping with righteousness (81–82; Romans 8).
Ephesians. The indwelling presence of the Spirit “builds believers together ‘into the temple in the Lord’ (Eph. 2:16, 21)” (83). Being “filled with the Spirit” refers to being controlled by the Holy Spirit (85).

Chapter 5: Adversity—Discipline and Suffering

This chapter focuses on the books of Hebrews and 1 Peter to show that suffering is integrally related to sanctification.

Hebrews. Believers are “instructed to accept an important means of growth and refinement toward maturity in their lives: God’s discipline” (95).
1 Peter. Köstenberger doesn’t give any new information in this section; it is quite repetitive. She does say that 1 Peter urges Christians to “focus on eternal pursuits and aim not to be distracted by worldly requests. This eternal pursuit entails growth in personal godliness—sanctification” (99).

Chapter 6: Legacy—Love and Virtue

This chapter covers the books of 1 & 2 Timothy, Titus, Jude, 2 Peter, 1 John, and Revelation. For the most part, this chapter says the same thing as the previous chapters, without adding much. Köstenberger has an added emphasis on virtues—as Christians focus on character, they will begin doing the right thing. Köstenberger did not focus much on Revelation and glorification, when sanctification is complete. This surprised me, because that is where Christians are heading.

Chapter 7: Practice—New Life in Christ

This is the best chapter in the book. It succinctly summarizes the main points that seemed to get lost at time in Köstenberger’s wordiness and pedantic desire to summarize every book of the New Testament.

“In Christ, believers are positionally sanctified through the gift of the indwelling Holy Spirit and empowered to work out their salvation in progressive sanctification, propelled toward moral excellence, missional community, and meaningful relationships. In Christ, they are assured of future perfect sanctification when glorified in his presence. In Christ, they desist from dead works and start living a new life—life in the Spirit” (124).