The use of Isa 59.17 in 1 Thess 5.8 — a biblical & theological examination

The Use of Isaiah 59.17 in 1 Thessalonians 5.8
By: Geoffrey R. Kirkland
Christ Fellowship Bible Church

The Texts:
MT — Isa 59.17:

  וַיִּלְבַּ֤שׁ צְדָקָה֙ כַּשִּׁרְיָ֔ן וְכ֥וֹבַע יְשׁוּעָ֖ה בְּרֹאשׁ֑וֹ וַיִּלְבַּ֞שׁ בִּגְדֵ֤י נָקָם֙ תִּלְבֹּ֔שֶׁת וַיַּ֥עַט כַּמְעִ֖יל קִנְאָֽה׃

(And He clothed Himself with righteousness as a breastplate, and a helmet of salvation on His head. And he clothed Himself with garments of vengeance as clothing. And he wrapped himself with zeal as with a cloak.)

LXX — Isa 59.17:
καὶ ἐνεδύσατο δικαιοσύνην ὡς θώρακα καὶ περιέθετο περικεφαλαίαν σωτηρίου ἐπὶ τῆς κεφαλῆς καὶ περιεβάλετο ἱμάτιον ἐκδικήσεως καὶ τὸ περιβόλαιον
(And He clothed himself with righteousness as a breastplate, and he put on a helmet of salvation upon His head and he put a garment of vengeance on himself even as a cloak.)

NT — 1 Thess 5.8:
ἡμεῖς δὲ ἡμέρας ὄντες νήφωμεν ἐνδυσάμενοι θώρακα πίστεως καὶ ἀγάπης καὶ περικεφαλαίαν ἐλπίδα σωτηρίας·
(But as for us, we are of the day, so let us be sober by clothing ourselves with a breastplate of faith and love and a helmet—the hope of salvation.)

The OT Context of Isaiah 59:
Isaiah 59 finds itself in the midst of the Servant Songs where, in this section of Isaiah’s prophecy, he provides hope and affirmation to the people of Israel that Yahweh, her God, would bring deliverance to her. This would find ultimate fulfillment in the Suffering Servant (ch.53). Isaiah, however, continued to note the free offer of mercy to those who would believe (ch.55) and the reward for obeying God (ch.56). In ch.57, God notes that he is high, exalted, lofty, and worthy of all worship (57:15). For this reason, Isaiah notes that man’s iniquities have separated him from God (59:2) and that no one can bring himself salvation (59:16). So God’s own arm brought salvation (59:16b) and in so doing, he put on righteousness like a breastplate, and a helmet of salvation on His head (59:17). He put on garments of vengeance and zeal as he will repay the wicked according to their deeds (59:17b-18). This salvation finds ultimate fulfillment in the Redeemer who comes to Zion (59:20).

The NT Context of 1 Thessalonians 5:
Paul penned the book of 1 Thessalonians to express his deep joy and worshipful delight that the young Church still walks faithfully with Christ even amidst persecutions. In chapters 1-3, Paul writes about the overview of the gospel (ch.1), the reminder of how he conducted himself with the church (ch.2) and the encouragement he received from Timothy’s visit to them & the report that he relayed (ch.3). Beginning in chapter 4, Paul provided a host of practical issues in response to God’s work of grace in their lives (chs.1-3). Such issues include sexual purity (4:1-8), loving the brethren (4:9-10), working hard (4:11-12), and the coming of the Lord Jesus for His people (4:13-18).

Beginning in chapter 5, Paul transitions to a new section (different from 4:13-18 but yet not an entirely unrelated topic) as marked by Περὶ δὲ (v.1). The believers in Thessalonika knew that the Day of the LORD would come unexpectedly as a thief (5:2b). Indeed, it would be a destructive period (5:3a) and one that is inescapable (5:3b). This Day of the LORD would dawn upon the unbelieving (note the pronouns: “they”, “them” in vv.3). But the believers, the Church, are not in darkness. They are, rather, sons of light and sons of the day (5:5). As a result of their position in Christ (being sons of light & sons of the day as opposed to sons of the night and sons of darkness), this must affect their practice in Christ. This must produce alertness and sobriety as they live life (5:6). It must markedly be different than the unbelieving world who drinks themselves drunk and sleeps at night and are totally unprepared for the coming of the Lord (5:7).

But the true believers, on the other hand (as opposed to those who get drunk at night in 5:7), are to be sober since they are of the day (5:8). And the way that believers are sober includes three elements. The believers must put on (lit. ‘clothe themselves with’; ἐνδυσάμενοι) the breastplate of faith, the breastplate of love, and the helmet, that is, the hope of salvation.

The breastplate of faith most probably refers to the element that covers the vital organs of a person (namely, one’s heart & central chest cavity). That which protects the believer’s most vital organs is none other than faith. It is faith in Christ, faith in the gospel, faith in what God has done (1:4) and in the power of the Word of God in bringing transformation (2:13), and  in the truth that Jesus rescues His people from the wrath to come (1:10).

The breastplate of love speaks to the most important characteristic of believers that distinguishes them from the unbelieving world — love. One’s love for God, love for the community of believers, for the Lord Jesus Christ, for the lost, and even for one’s enemies sets him apart from the unregenerate. This is the breastplate that guards the believer.

The helmet which is the hope of salvation indicates that the salvation produces a hope that launches a believer to live for the next world. It thrusts the eternal mindset upon the believer. This eternal and certain hope guides him, guards him, governs him, and encourages him as he treks through life.

All of this shows that the believers are “sober” and are of the day and of the light as opposed to the darkness and the night. Live by putting on the breastplate of faith, love, and the hope of salvation as a helmet which marks a person out as diametrically opposed to the nonbelieving world.

The Way Paul Uses the OT:
In Isaiah 59:17, God is the one who brings salvation to His people who are totally incapable of bringing deliverance to themselves. He does this by putting on righteousness ass a breastplate and salvation as a helmet on his head. God is the one who brings salvation. God does the doing in the OT text.

In the 1 Thess 5 text, Paul writes that believers are to show that they are children of the day/light by putting on, or, clothing themselves with the breastplate of faith, love, and with the helmet of hope. This is the believer’s responsibility in the NT text.

Thus we see the antinomy that the believer is to apply these elements to his own life but yet, ultimately, as Paul shows in bringing the language in from Isa 59.17, it is only God Himself who ultimately gives the ability to be clothed with these elements. Thus, it is God who works these things in His people but at the same time it is the responsibility of believers to put these on and practice them in their own lives to show that they are truly sons of the true God of Light. Indeed, the faith, hope, and love which the believer is to put on points to the unmistakable reality that the person is a son of the day. This triad of virtues ties it in with the entire letter as in 1:3 Paul spoke of the believer’s work of faith, labor of love, and steadfastness of hope. All of these virtues must, out of necessity, be constantly practiced and “put on” in the life of the son of light.

The Theological Implications:
Ultimately, 1 Thess 5.8 can only be accomplished through the sovereign working and enabling of God in the lives of His people. Only God is the one who can bring righteousness as a breastplate. Only God is the one who can bring the helmet of salvation. Only God saves. Paul made this point in 1 Thess 1:9-10.

But at the same time, the believers are to utilize the power of God in their sanctification and conduct as they practice their position by putting on the breastplate of faith, love, and the hope of salvation (as a helmet).

There is an enjoining together of the work of God in sanctification and the work of the believing saint in arming himself with faith, hope, and love. Ultimately these are all sourced in God. Yet the believer must, by God’s grace and through His enabling, put on — that is, clothe himself with — these articles as they live lives of sobriety, self-control and thus show themselves to be children of light and sons of the day.

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