Summary: The topic of "God's plan for the nations" is viewed within the Biblical framework of God's plan of salvation for Jews and Gentiles. The fulfillment of the Great Commission is viewed as binding on the body of Christ as a whole unit, thus each member is responsible for neither more nor less than making use of the gifts he has received.

God's Plan for the Nations

   In Genesis 11 the whole earth had one language and the same words. They said to themselves, "Come, let us build ourselves a city and a tower with its top in the heavens, and let us make a name for ourselves, lest we be dispersed over the face of the whole earth." It seems that their project greatly offended the Lord. Some people have suggested that they had invented their own religion, and were trying to reach heaven on their own terms. Others have suggested that in their proud self-sufficiency they thought they could outsmart God and be prepared if He sent another flood. (Thus the great height of the tower, and the "tar" used for mortar. The Hebrew word for "tar" here is the same word used in Exodus 2:3, with which Moses' mother coated the basket of reeds so it would be waterproof.) But in any case, all we know from the text itself is that the people's reason for building the tower was "so that we may make a name for ourselves". And that, in itself, seems to be what kindled the anger of God. So the Lord scattered them from there over all the earth and He confused their languages.
   Again, note that up until this point the whole world had one language and a common speech. When God dispersed them over the face of the earth and confused their languages, this was the beginning of the diversity of the nations as we know them today. But of course, God's plan for the nations had only just begun.
   God then appeared to one particular man, Abram, and said, "Go from your country and your kindred and your father's house to the land that I will show you. And I will make of you a great nation, and I will bless you and make your name great, so that you will be a blessing. I will bless those who bless you, and him who dishonors you I will curse, and in you all the families of the earth shall be blessed." Via this promise, Paul says, God preached the gospel to Abraham. (Gal 3:8)
   God did proceed to make from Abraham a great nation, Israel. And God did continue to bless Israel in many ways. First of all, they were entrusted with the very words of God. (Rom 3:2) Indeed, to them belong the adoption, the glory, the covenants, the giving of the law, the worship, and the promises. Theirs are the patriarchs, and from them is traced the human ancestry of Christ, who is God over all, forever praised! Amen. (Rom 9:4-5)
   But how would the God of the whole earth make Abraham and Israel to be a blessing to all the nations? Well, there are many glimmers of this throughout the Old Testament. Any non-Israeli, such as Rahab and Ruth, who was willing to "bind themselves" to the Lord of Israel would be taken into His people. (Isa 56:3a) Indeed, foreigners could voluntarily come under the covenant of circumcision (Gen 17), and if so, they could enjoy the same benefits as native-born Jews. (Ex 12:48-49) Even aliens temporarily living amongst Israel were in many ways treated according to precisely the same legal system (Lev 24:21-22), and given protections to ensure proper treatment in Israel. (Ex 20:10, 22:21, Lev 19:10) They could enjoy some of the benefits of God's tabernacle and the sacrificial system. (Num 15:14-16) God sent some of His prophets from Israel, such as Jonah, to speak His word to other nations. And through the Jewish prophets, God foretold of many ways in which He planned to treat Israel and the rest of the nations equally. (Isa 19:23-25, 49:6; Dan 7:14; Mic 4:1-5)
   But even with all of that, it must be admitted that all the evidence would show that, up to the end of the Old Testament, God's blessings to Abraham's family FAR exceeded His blessings through Abraham to all the families of the earth. There is just no comparison. Indeed, even though Paul says that God "preached the gospel to Abraham" (Gal 3:8), Paul also numerous times speaks of the mystery of the gospel that he preaches to the nations, which was kept secret and hidden for long ages. (Rom 16:25, Eph 3:1-9, 6:19, Col 1:26-27, 4:3)
   When Messiah arrives He doesn't immediately, radically overturn this situation. He says, "I was sent only to the lost sheep of Israel." (Mt 15:24) And He sends His apostles to preach only to the lost sheep of Israel, explicitly commanding them not to go to the Gentiles. (Mt 10:5-6) But in various ways He begins to display a plan for the nations. After seeing the response of faith in the centurion, He says, "I tell you the truth, I have not found anyone in Israel with such great faith. I say to you that many will come from the east and the west, and will take their places at the feast with Abraham, Isaac and Jacob in the kingdom of heaven. But the subjects of the kingdom will be thrown outside, into the darkness, where there will be weeping and gnashing of teeth." (Mt 8:10-12) And He shows mercy to the same Canaanite woman to whom He said, "I was sent only to the lost sheep of Israel." As with the centurion, He takes special note of her faith. (Mt 15:28)
   But I would say that the more Jesus nears the cross, the more He unfolds His plan for the nations. He says that this gospel of the kingdom (which He has been preaching and demonstrating) shall be preached in the whole world as a testimony to all the nations, and then the end will come. (Mt 24:14) In His explanation of the coming Judgment over which He will preside, He gathers all the nations together, and treats them in the same manner, irregardless of Jew or Gentile. (Mt 25)
   But after His resurrection, Jesus' intention for the nations becomes unmistakably clear. He commands His apostles to make disciples of all nations (Mt 28:19), to go into all the world and proclaim the gospel to the whole creation. (Mk 16:15) Indeed, after opening their minds to understand the Scriptures, He says to them, "Thus it is written, that the Christ should suffer and on the third day rise from the dead, and that repentance and forgiveness of sins should be proclaimed in his name to all nations, beginning from Jerusalem." (Lk 24:45-47) In other words, the fact that the gospel of Christ is for ALL the nations had already been declared in the (Old Testament) Scriptures, for those who have eyes to see it.
   Nevertheless, the disciples remain a bit slow in catching on to this profound insight. Peter (Acts 10) and Paul (Acts 9:15; Gal 1:12, 15-16) both receive a direct supernatural revelation to help them understand that the gospel of Jesus Christ is for all the nations. Paul in particular is set apart as apostle to the Gentiles, and God makes especially clear to him the implications of this. (Gal 2) Namely, if salvation is by faith in Christ, with no distinction between Jew and Gentile (Rom 10:8-13), then there is absolutely no need for Gentiles to be brought under the Law of Moses and the covenant of circumcision. (Compare Ex 12:48-49; Ez 44:6-9) This sets Paul up for a head-to-head debate against the Judaizers who said that the Gentiles must be circumcised and required to obey the Law of Moses in order to be saved. (Acts 15:1-5) The Jerusalem Council, presided over by the apostles and elders, sides with Paul, affirming that all along the Scriptures have foretold that God intended to take from the Gentiles a people for himself. (Acts 15:14-18)
   From that point onward, there is no doubt that the "mystery" of the gospel is secret no more. Paul makes it explicit that the "mystery" long kept hidden is that the Gentiles are fellow heirs [with Israel], members of the same body, and partakers of the promise in Christ Jesus through the gospel. (Eph 3:6) Indeed, Gentiles who trust in Christ are grafted in to the olive tree of Abraham and Israel. (Rom 11:17-24)
   It is from this perspective, I believe, that Paul offers a profound insight into Jesus' words during His earthly ministry, "I was sent only to the lost sheep of Israel." Paul says that that Christ became a servant to the circumcised [Israel] to show God's truthfulness, in order to confirm the promises given to the patriarchs, and in order that the Gentiles might glorify God for his mercy. (Rom 15:8-12) Remember that the gospel to the Gentiles is that they can partake in the inheritance and the promises of Israel. Put more graphically, but just as Biblically, the gospel to us Gentiles is that Messiah will take the children's bread and give it even to us dogs, if we come to Him in faith. The fact that Messiah came as servant to the Jews, and yet He even shares their bread with us dogs, should make us glorify God for His mercy.
   Finally, God's plan for the nations comes to a completion when He gathers together all who are descendants of Abraham by faith, to come and worship and make HIS name great, rather than trying to make their own name great like they did at Babel. They will sing, "Who will not fear you, O Lord, and bring glory to your name? For you alone are holy. All nations will come and worship before you, for your righteous acts have been revealed." (Rev 15:4) Rather than uniting in self-serving rebellion against God as one people under one language like they did at Babel, now God receives the glory from the great diversity of a great multitude that no one could count, from every nation, tribe, people and language, standing before the throne and in front of the Lamb. (Rev 7:9)

   So indeed, the Bible's story of God's plan for the nations is largely the story of God's plan for the Jews and for the Gentiles as promised to Abraham, and how the two distinct paths differ but intersect for long ages in a shrouded mystery, and finally collide in the gospel of righteousness by faith in Jesus Christ apart from the Law. For a modern Gentile Christian to express disinterest in God's plan for the nations is a great hypocrisy. If you are a Gentile follower of Messiah, you are God's plan for the nations, your very salvation hinges on God's merciful plan for the nations.
   Thus, when viewed from the Jew/Gentile paradigm, "God's plan for the nations" is clearly one of the most fundamental Biblical themes. Indeed, when considering the question, "How does God's plan of salvation incorporate the Gentiles?", it becomes apparent that a satisfying Biblical missiology (theology of missions) is contained within a Biblical soteriology (theology of salvation). I think that becomes even clearer as we continue.

Our Response

   After taking a view of the magnificent works God has done it is natural, and indeed proper, for us to ask, "How then shall we respond?" So let's take a closer look at some of the major imperatives or applications which come as a result of God's plan for the nations as foretold and fulfilled in Christ.

   In summary, then, as Acts carries on we see the Great Commission being fulfilled through the interweaving lives and ministries of many different people doing many different things. It is clear that there is no earthly mastermind organizing and strategizing how it will all work together and work out. Christ is clearly the one who is head of His body, and His work on earth is fulfilled as each individual member does its own part.
   Although we see many people doing many different ministries in Acts, there are at least four that are given titles: apostle (e.g. 14:14), prophet (11:27, 13:1, 15:32, 21:10), evangelist (21:8), and teacher (13:1). Some Reflections on "Missiology"

   I believe in the above I have expressed a "theoretical" doctrine of Biblical missiology which fits within a doctrine of God's plan of salvation through the ages, and a "practical" doctrine of missiology which fits within a doctrine of spiritual gifts. The question of God's plan for the nations is answered by the gospel of Christ in which Jew and Gentile alike are made righteous in Him through faith, not by our own obedience to the Law of Moses. The question of what are each of us to do about the Great Commission is answered by the parable of the talents and the imperatives about our gifts, that each of us is responsible to make use of that which He has given us, for the building up of the body and for the glory of God. As the Spirit and His gifts are given to us as a promise in our salvation (Acts 2:38-39), likewise this practical missiology flows very naturally from this theoretical missiology.
   In light of this, and other considerations, I personally find that the issues and questions which nowadays are considered to fall under the category of "missions" are actually best answered without recourse to a distinct "missions" vocabulary or distinct "missions" theology. Rather, all of the relevant matters can best be handled in the larger context of "normal" Biblical principles and "non-missions" vocabulary.