Old Testament passages that describe Israel or her king conquering the nations in the future occur because Jesus conquers the nations as the king of Israel by the cross and resurrection. So he conquers by faith. Yet this does not preclude his conquering by force those who do not believe when he returns.
One of the most unrealized yet central scriptural patterns of New Testament proclamation is Christ’s fulfillment of eschatological promises. This fulfillment of the universal and eschatological passages in the Old Testament is the reason why the Gospel goes to all nations.
Through Christ, the end has begun to be realized. The Gospel, by its very nature, is eschatological. It is the last hour. The kingdom of God is near. Hence, the Gospel saves all who believe since Jesus reigns over all creation.
In this regard, the New Testament applies passages about the subjugation of gentiles to the church. To be more accurate, the New Testament sees Gentile conquest passages as first all a subjugation by faith and inclusion into the people of God. And then second, in the end, these passages point to Christ’s subjugation of the nations by force (e.g., Rev 19).
Let me explain how this works before spending time in Romans 15 to see an important example of this apostolic proclamation in practice.
Jesus is the King of Israel and Ruler of Nations
The Old Testament prophecies of the nations submitting to Israel—these universal promises—are the reason why the Gospel goes to the nations. In Christ, the king of Israel, the nations kneel—they enter the kingdom through Christ. John says Christ “made us a kingdom” (Rev 1:6). So he shares in the tribulation and kingdom of the saints in Christ (1:9), who is “the ruler of kings on earth” (1:5).
That Christ rules the earth and that in him the church is the kingdom goes a long way in explaining why some conquest passages in the Old Testament now apply to the church. For example, James in Acts 15:13–17 cites Amos 9—in which a rebuilt Israel will conquer the nations—to argue for the inclusion of the gentiles in the church as gentiles and so not requiring Jewish works of the law.
Welcoming the Gentiles (Romans 15)
To show how this works, it is instructive to turn to Romans 15. Here, Paul cites a number of passages from the Old Testament to explain why Gentiles can praise God for his mercy. More particularly, Paul instructs believers to accept one another as Christ accepted them:
Accept one another, then, just as Christ accepted you, in order to bring praise to God. For I tell you that Christ has become a servant of the Jews on behalf of God’s truth, so that the promises made to the patriarchs might be confirmed and, moreover, that the Gentiles might glorify God for his mercy. (Rom 15:7–9).
Note the key lines of thought here. Christ serves Jewish people, fulfills the promises, and moves the Gentiles to glory in God’s mercy.
To verify these points, Paul cites Scripture:
As it is written: “Therefore I will praise you among the Gentiles; I will sing the praises of your name.” (Ps 18:49; 2 Sam 22:50)
Again, it says, “Rejoice, you Gentiles, with his people.” (Deut 32:43; Isa 66:10)
And again, “Praise the Lord, all you Gentiles; let all the peoples extol him.” (Ps 117:1)
And again, Isaiah says, “The Root of Jesse will spring up, one who will arise to rule over the nations; in him the Gentiles will hope.” (Isa 11:10; Rom 15:9–12)
This passage may be the most remarkable set of scriptural proofs for gentile inclusion in the whole of the apostolic writings. Consider each in turn.
1. Psalm 18
Paul here varies between citing scriptural passages as surprisingly addressing the church and/or as submitting the rule of the king of Israel by faith rather than by military conquest. In the first citation, David sings of God’s victory over David’s enemies. He speaks of “the God who gave me vengeance and subdued peoples under me” (Ps 18:47). He continues to understand God as exalting “me above those who rose against me” (Ps 18:48).