Now may the God of peace Himself sanctify you entirely; and may your spirit and soul and body be preserved complete, without blame at the coming of our Lord Jesus Christ. Faithful is He who calls you, and He also will bring it to pass. (5:23–24)

Paul’s concluding benediction points to the only source of power for obeying all the exhortations of 4:1–5:22—God, who alone sanctifies the obedient believer. Sanctification is inseparably linked to saving faith, because those whom God justifies He also sanctifies (cf. Rom. 8:28–29). The apostle Paul began this epistle with testimony that the Thessalonians had truly responded in saving faith to his gospel preaching and been justified (1:2–5; 2:1, 12–13), and here at the conclusion, he prayed for their complete sanctification. His prayerful benediction for them in these verses reveals several essential elements of sanctification: its nature, source, and extent; its human components; its goal and culmination; and its final security.

SANCTIFICATION’S NATURE, SOURCE, AND EXTENT

Now may the God of peace Himself sanctify you entirely; (5:23a)

Sanctify (hagiazō) means, “to set apart,” “to separate” from sin to holiness. The optative mood here expresses a wish or desire. The noun form occurs several other times in this letter (4:3–4, 7) and the verb a number of times elsewhere in the New Testament (John 10:36; 17:17, 19; Acts 20:32; 26:18; Rom. 15:16; 1 Cor. 1:2; 6:11; 7:14; Eph. 5:26; 1 Tim. 4:5; 2 Tim. 2:21; Heb. 2:11; 9:13; 10:10, 14, 29; 13:12; 1 Peter 3:15). Sanctification is the ongoing spiritual process by which God increasingly sets believers apart from sin and moves them toward holiness. The apostle’s entreaty for the Thessalonians parallels and reiterates the theme and form of his earlier prayer for their spiritual growth in 3:11–13:

The concept of sanctification, setting things apart to God, is one of the oldest in Scripture. In Genesis 2:3 God Himself sanctified the seventh day and rested from His creative work. Job regularly made burnt offerings to God and consecrated his sons to Him (Job 1:5). At the Exodus, God set apart the firstborn of His people and their animals for His use (Ex. 13:1–2). Just prior to God’s giving Moses the Ten Commandments, He set apart Israel as a holy nation (Ex. 19:5–6; cf. Ezek. 37:28) and a few days later sanctified Mount Sinai (Ex. 19:23), having already forbidden the Israelites from coming too near it (v. 12). Later in the wilderness, the Lord sanctified Aaron and his sons for the priestly office (Ex. 28:41 ff.) and set apart the tabernacle and its vessels for sacred purposes (chaps. 30–31; 35–40). Samuel sanctified Jesse and his son David (1 Sam. 16:5, 12–13). Many years later God sanctified the temple in Jerusalem (2 Chron. 7:16). Before the prophet Jeremiah was even born, God set him apart for prophetic ministry (Jer. 1:5).

New Testament narratives also contain examples of God’s special sanctifying work. He set apart John the Baptist to be the forerunner of Jesus Christ (Luke 1:13–17). God the Father also set apart His Son the Messiah for the work of redemption (Matt. 1:20–23; Luke 1:31–33; cf. 2:29–35; Matt. 3:13–17; Acts 2:22–24). Jesus set apart the twelve apostles from the larger number of disciples who followed Him (Mark 3:13–19; Luke 6:12–16). The early church set apart for divine service the first deacons (Acts 6:1–6) and some for missionary service (13:1–3).

Three basic elements define believers’ sanctification. First is the past, fixed aspect—positional sanctification—which God effected at the time He saved each believer. God secured positional sanctification through the death of His Son: “We have been sanctified through the offering of the body of Jesus Christ once for all…. For by one offering He has perfected for all time those who are sanctified” (Heb. 10:10, 14). By that atoning work, God rescued all believers from the dominion of sin and spiritual darkness and placed them into the dominion of His righteousness and spiritual light. Believers also receive a new nature at salvation: “Therefore if anyone is in Christ, he is a new creature; the old things passed away; behold, new things have come” (2 Cor. 5:17; cf. 2 Peter 1:4). The indwelling Holy Spirit signifies the believer’s new nature (Rom. 8:9). God imputes Christ’s righteousness to believers so that He sees them not as sinners, but as those sanctified, covered with the righteousness of Christ (cf. Rom. 3:21–25; 2 Cor. 5:21; 1 John 4:10). As a result, God declares them holy and calls them “holy ones” or “saints” (cf. Rom. 1:7; 1 Cor. 1:2; 2 Cor. 1:1; Eph. 1:1).

Sanctification has a second, future aspect—ultimate sanctification—when God actually makes believers sinless in body and spirit forever. Paul assured the Philippians, “For our citizenship is in heaven, from which also we eagerly wait for a Savior, the Lord Jesus Christ; who will transform the body of our humble state into conformity with the body of His glory” (Phil. 3:20–21; cf. Rom. 8:30; 1 Cor. 15:52–54; 1 John 3:2–3). In ultimate sanctification, God joins the new nature, then relieved of the debilitating flesh, to transformed and glorified bodies for all eternity. It is the promised realization of the church being presented as a bride without spot or blemish to her Bridegroom, Jesus Christ (Rev. 19:7–8; 21:2, 9; cf. Eph. 5:26–27; Col. 1:21–23).

The third element defining biblical sanctification is the experiential aspect, which concerns present Christian living and thus lies between the past/positional and future/ultimate aspects of sanctification. It is the process in which believers strive, by the Spirit’s power, to be more and more conformed to the image of Christ. Paul summed it up in 2 Corinthians 3:18: “But we all, with unveiled face, beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as from the Lord, the Spirit” (cf. Rom. 12:9–21; 15:4–7; 2 Cor. 9:6–12; Gal. 5:16–6:10; Eph. 4:1–6:18; Phil. 2:1–4, 14–15; 3:15–17; 4:4–9; Col. 3:1–4:6; 1 Thess. 3:11–13; 4:3–12; 2 Thess. 2:13–15; 3:7, 13; 1 Tim. 4:12–16; 6:11–14; 2 Tim. 1:6–10; Titus 3:1–8; Heb. 12:12–15; 13:1–9; James 1:2–27; 3:13–18; 1 Peter 3:1–12; 2 Peter 1:5–11; 1 John 1:5–9). Experiential sanctification is the pursuit of holiness (cf. Matt. 5:48; 1 Peter 1:14–16). The Puritan Thomas Watson stated it this way, “[Sanctification] is a principle of grace savingly wrought, whereby the heart becomes holy, and is made after God’s own heart. A sanctified person bears not only God’s name, but His image” (Body of Divinity [reprint; Grand Rapids: Baker, 1979], 167). In all of Paul’s epistles, whenever he moves from doctrinal exposition to practical exhortation, he has this aspect of sanctification in mind. His passionate prayer for the Thessalonians and for all believers was that through experiential sanctification God would progressively conform them to holiness.

God is the source of sanctification. After giving the Thessalonians a series of commands and exhortations that called for them to put forth disciplined, devoted effort (5:12–22; see also 4:1–8, 11–12, 18; 5:6, 8, 11), Paul wanted them to recognize that ultimately it is God who enables believers to obey those admonitions and progress in sanctification (cf. Phil. 2:13). Centuries earlier the prophet Zechariah made that principle clear: “‘Not by might nor by power, but by My Spirit,’ says the Lord of hosts” (Zech. 4:6). Regarding his own ministry, Paul understood the principle well: “We proclaim Him, admonishing every man and teaching every man with all wisdom, so that we may present every man complete in Christ. For this purpose also I labor, striving according to His power, which mightily works within me” (Col. 1:28–29; cf. 1 Cor. 2:1–5; Eph. 3:20). However, Paul’s assertion to the Colossians also reveals the inseparable link between human effort and divine power in living the Christian life. Believers must yield themselves to God (Rom. 6:19; 12:1–2) and diligently pursue holiness (1 Cor. 9:24–27; 2 Tim. 4:7; 2 Peter 1:5–11), yet always proceed in humble dependence on Him (cf. 1 Cor. 15:10; Gal. 2:20).

From a human standpoint, it is impossible to fully understand how this symbiosis works (cf. Deut. 29:29; Isa. 55:9). Paul summarized this unfathomable process best when he told the Philippians, “So then, my beloved, just as you have always obeyed, not as in my presence only, but now much more in my absence, work out your salvation with fear and trembling; for it is God who is at work in you, both to will and to work for His good pleasure” (Phil. 2:12–13; cf. Gal. 2:20). Christians are to live out in their daily lives the salvation God has wrought in them.

Paul chose to identify the Lord with the familiar scriptural expression the God of peace (cf. Rom. 15:33; 16:20; 1 Cor. 14:33; 2 Cor. 13:11; Phil. 4:9; Heb. 13:20). Peace (eirēnē) is the best word to summarize God’s saving work, which is why the New Testament often uses it to describe Him (cf. Luke 19:38; John 14:27; Rom. 1:7; 1 Cor. 1:3; 2 Cor. 1:2; Eph. 2:14; 2 Thess. 3:16). It denotes not just some existence, situation, or state of mind free from conflict, but the composite of gospel blessing. Paul is not speaking of God’s own tranquility, but the peace of salvation He provides through the cross of Christ for all who repent and believe (Isa. 53:5; Rom. 5:1; Eph. 2:14–15; Col. 1:20; cf. Luke 1:79; 2:14; John 14:27; Acts 10:36; Rom. 10:17).

To underscore that it is God who sanctifies, the apostle used Himself (autos) in the emphatic position. God does not delegate the sanctifying process to an angel or an apostle; neither does He accomplish it by some distant decree. Rather He accomplishes it by His own actions as He works directly in believers’ lives.

Entirely is used only here in the New Testament and is a compound of two Greek words, holos, “whole,” “complete,” and telēs, “end,” “finish.” Paul asked that God would sanctify the Thessalonians “all the way through,” or “through and through”—that sanctification would leave no part of their inner beings unaffected.

SANCTIFICATION’S HUMAN COMPONENTS

and may your spirit and soul and body (5:236)

The sanctifying work of God includes not only the immaterial part of the believer (spirit and soul), but also the body. (Paul is not here referring to glorification, because he desired that the element of sanctification now mentioned be true of the Thessalonians when Christ comes, not after.) In view of the prevailing Greek culture, it is significant that Paul included the body in his benediction. That culture—influenced by a philosophical dualism which taught that man’s spirit is inherently good and his body inherently evil—held the body in low esteem. That philosophy provided a convenient rationale for dismissing as inconsequential whatever immoral physical behavior people might have engaged in.

But such thinking was abhorrent to the apostle Paul; he later exhorted the Corinthians, “Do you not know that your body is a temple of the Holy Spirit who is in you, whom you have from God, and that you are not your own? For you have been bought with a price: therefore glorify God in your body” (1 Cor. 6:19–20; cf. Luke 11:36; Rom. 6:12–13; 8:13; 12:1; 1 Cor. 6:13, 15; 9:27; Col. 2:23; 3:5; James 3:2–3, 6). If sanctification is to be complete, it will extend to every part of the believer, especially the body, which thinks, feels, and acts in response to the holiness of the inner person.

There has been a significant debate over the years about the definition and usage of the terms spirit and soul. Some (historically called trichotomists) believe Paul was identifying two different, distinct categories of the nonmaterial essence of man. Those parts, along with the body, make man a three-part being. Others (historically called dichotomists) believe spirit and soul are interchangeable words denoting man’s indivisible inner nature. Those interpreters therefore view man as a two-part being, composed simply of a nonmaterial nature (spirit and soul) and a material nature (body).

No Scripture text ascribes different, distinct substance and functions to the spirit and soul. Trichotomists nevertheless usually propose that spirit is man’s Godward consciousness and soul is his earthward consciousness; however, neither the Greek usage of spirit (pneuma) nor of soul (psuchē) sustains that proposition. The nonmaterial part of man does have myriad capacities to respond to God, Satan, and the world’s many stimuli, but it is untenable to arbitrarily separate the spirit from the soul. The two terms are used interchangeably in Scripture (cf. Heb. 6:19; 10:39; 1 Peter 2:11; 2 Peter 2:8). Spirit and soul are familiar and common synonyms that Paul used to emphasize the depth and scope of sanctification. Some suggest that an acceptable translation of this portion of Paul’s prayer could be, “May your spirit, even soul and body,” in which case “spirit” would refer to the whole person, and “soul and body” to the person’s nonmaterial and material parts. References from Paul’s other epistles provide clear evidence that he was a dichotomist (Rom. 8:10; 1 Cor. 2:11; 5:3, 5; 7:34; 2 Cor. 7:1; Gal. 6:18; Col. 2:5; 2 Tim. 4:22).

Some claim Hebrews 4:12, “For the word of God is living and active and sharper than any two-edged sword, and piercing as far as the division of soul and spirit, of both joints and marrow, and able to judge the thoughts and intentions of the heart,” supports a trichotomist view of man’s essence because it suggests splitting soul and spirit. But a careful look at the verse’s language refutes that contention. The writer did not say the sword of the Word penetrates a person’s inner being and separates his soul from his spirit. He said only that the sword cuts open the soul and the spirit of the person. He used a second metaphorical expression “piercing … both joints and marrow” to further depict the deep penetration God’s Word makes into the inner person. This verse poses no special difficulty for the dichotomist position.

SANCTIFICATION’S GOAL AND CULMINATION

be preserved complete, without blame at the coming of our Lord Jesus Christ. (5:23c)

Complete (holoklēros) means “with integrity,” “total,” “intact,” “undamaged,” and perfectly conforms with Paul’s and his Lord’s desire for the church to be holy, without blemish or defect (Eph. 5:25–27; cf. 2 Cor. 6:16; 11:2; 1 Tim. 3:15; 1 Peter 2:5; Rev. 19:7–8; 21:2).

This portion of Paul’s prayer is also consistent with the personal goal he later expressed to the Philippians: “I press on toward the goal for the prize of the upward call of God in Christ Jesus” (Phil. 3:14). The prize of being called up to heaven is eternal holiness and Christlikeness. And meanwhile the apostle had, as much as possible, the same earthly goal, which meant pursuing Christlikeness. He said it was the one thing he did (3:13). In the wondrous balance of diligent effort and divine power that is in every aspect of salvation, Paul prayed that the saints would be preserved (“kept”), that God would keep them in the path of holiness until they received their ultimate sanctification (cf. Matt. 24:13; Acts 13:43; 14:22; Eph. 6:18; Col. 1:21–23; Heb. 12:2–3). His desire was that God would bring them to that point without blame. Without blame (amemptōs) is the same word archeologists have found on Christian tombs from ancient Thessalonica. When people wanted to identify a deceased friend or loved one as a Christian, they inscribed “blameless” on his or her grave — and behavioral blamelessness (not just the imputed and forensic) is the Lord’s desire for His church (cf. Eph. 5:26–27).

At the coming of the Lord Jesus Christ, God will make all believers sinless forever. First Corinthians 15:50–54 affirms that reality:

This is the letter’s fourth mention of His coming (parousia) and, as with the other occurrences (2:19; 3:13; 4:15), it is again a reference to the Rapture of the church. Paul prayed that when the Lord Jesus Christ comes for believers He will find them faithfully pursuing the goal of being as holy as their Lord and longing to receive the promised heavenly perfection.

SANCTIFICATION’S FINAL SECURITY

Faithful is He who calls you, and He also will bring it to pass. (5:24)

God who calls is also faithful to complete and bring … to pass His sanctifying purpose. Paul later expressed to the Philippians this confidence in God’s faithfulness to believers: “For I am confident of this very thing, that He who began a good work in you will perfect it until the day of Christ Jesus” (Phil. 1:6). That is another pledge to all believers that God has the power to guarantee their ultimate sanctification. The salvation God grants is secure—He graciously and efficaciously calls individuals (John 6:37, 44–45, 64–65), supplies them the faith to repent and believe (Eph. 2:8–9; cf. 2 Tim. 2:25–26), and provides them the grace to persevere to the glory of ultimate sanctification (Jude 24–25; cf. 1 Cor. 10:13). Romans 8:28–30 also states this pledge:

In summary, Paul’s prayer for the Thessalonians suggests a number of essential principles that all Christians need to remember concerning the sanctification process. First, experiential sanctification is inherently both negative and positive. Negatively, it involves the purging out of sin (cf. Rom. 6:6; 8:13; 2 Tim. 2:19). Scripture compares sin to leaven (cf. Matt. 16:12; 1 Cor. 5:6–8; Gal. 5:8–9), which connotes the evil influence with which sin permeates humanity. Sanctification does not remove the presence of sin, but it purges from the believer his love for sin and decreases sin’s frequency in his life (cf. Rom. 6:22; 7:21–25; Phil. 3:7–16; Titus 2:11–12). Positively, sanctification involves the renewing of the mind (cf. Rom. 12:2) and the putting on of Christlikeness (cf. Col. 3:5–17). The negative and positive changes occur as the Holy Spirit continually uses God’s Word in believers’ lives (John 17:17; 2 Tim. 3:16–17; cf. John 15:1–3).

Second, sanctification occurs chiefly in the heart, the mind, the inner being. It is not concerned with modifying one’s outward behavior—even if that behavior were in line with God’s law—apart from the changed heart (cf. Rom. 3:21–23, 28; 4:4–5; 5:1–2), nor is it circumscribing one’s attitudes and actions to an arbitrary code of ethics (cf. Rom. 14:17; Col. 2:16–23). Sanctification does affect a Christian’s outward actions (cf. John 15:4–5; Eph. 2:10), but it is essentially an inward grace. It is illustrated by what the apostle Peter wrote to believing wives: “Your adornment must not be merely external—braiding the hair, and wearing gold jewelry, or putting on dresses; but let it be the hidden person of the heart, with the imperishable quality of a gentle and quiet spirit, which is precious in the sight of God” (1 Peter 3:3–4).

Third, the Bible implicitly calls sanctification a beautiful reality (cf. Ps. 110:3 KJV). Holiness is the beautiful crown jewel of the Godhead, reflecting divine perfection, unmitigated virtue, absolute righteousness, and pure sinlessness (cf. Ex. 15:11; Pss. 47:8; 145:17; Isa. 57:15). Sanctification, then, is a noble experience, imparting to believers a measure of the majesty God intended for them when He created mankind in His image (cf. Gen. 1:26–27; Ps. 8:4–6).

Fourth, sanctification is an ongoing reality. At the new birth, God plants the seed of righteousness, the principle of divine life, into the believer’s heart (cf. 1 Peter 1:23–25). That does not mean he will never sin again, but it does mean he will discontinue living in his previous unbroken pattern of sinfulness and begin to live in a new pattern of holiness (cf. Rom. 6:17–18; 1 John 3:9).

Fifth, believers must remember that people can counterfeit sanctification in a number of ways. First, moral virtue can substitute for true sanctification. People can exhibit character qualities such as fair-mindedness, loyalty, civility, kindness, generosity, diligence, and philanthropy and yet at heart be unbelievers (cf. Isa. 29:13). Second, religious activity can masquerade as sanctification. For example, devoutly religious people might spend years avoiding the most heinous sins and seeking to please God by adhering to their church’s rituals and self-righteously engaging in good works (cf. Matt. 23:23–25; Luke 18:10–14). But they do it all because they are afraid of God and want to earn His forgiveness, not because they are His children who sincerely love Him for His grace. Third, outward Christian profession can appear to be genuine sanctification (cf. Matt. 23:27–28). It often parades a hypocritical type of piety that is merely superficial (cf. Matt. 7:21–23). Such false sanctification deceives not only those who witness it, but also those who practice it. Fourth, their conscience and fear of sin’s consequences often restrain people from bad behavior. Most of the time they reject sin because they fear its negative physical, psychological, or even legal consequences. They may have grown up in a Christian family in which their parents taught them biblical principles and established a doctrinal foundation that informs their consciences with moral convictions. Such people are afraid to engage in overt sin and on the exterior appear to be righteous, but only because they do not want a guilty conscience to bother them. A saving love for Christ does not motivate their behavior; instead, human fear and a sensitive conscience drive their actions.

Sixth, sanctification keeps believers from polluting holy things. “To the pure, all things are pure; but to those who are defiled and unbelieving, nothing is pure, but both their mind and their conscience are defiled” (Titus 1:15). Unbelievers mock and blaspheme God and His Son (cf. Luke 22:65; Rom. 8:7; Col. 1:21; Rev. 16:9). They ridicule the things of God and the people of God (cf. Neh. 2:19; Ps. 38:12; 2 Tim. 3:3–4), which means they also ridicule and demean the Word of God (cf. Neh. 9:28–29). They pollute everything God has designed for His glory and mankind’s blessing (cf. Rom. 1:21–32), such as the beauty of creation, marriage, and friendship. By contrast, when God is sanctifying believers, they consider the simplest, most mundane things in life as holy and respect all the things the unbeliever does not (cf. Ps. 1:1–6).

Finally, Christians must remember that sanctification is God’s priority for their lives. It is His will for them (1 Thess. 4:3; cf. Heb. 12:14) and the result of Christ’s death on their behalf—“who gave Himself for us to redeem us from every lawless deed, and to purify for Himself a people for His own possession, zealous for good deeds” (Titus 2:14). All believers are to live for sanctification. They have no other goal in life than to be like Jesus Christ: “The one who says he abides in Him ought himself to walk in the same manner as He walked” (1 John 2:6).