A selection of verses showing that both Jews and non-Jews can be involved in God's plan.
The promise God makes to Abraham makes it clear that all nations can be involved through his offspring:
3 I will bless those who bless you, and I will curse him who treats you with contempt. All the families of the earth will be blessed through you.”
17 that I will bless you greatly, and I will multiply your offspring greatly like the stars of the heavens, and like the sand which is on the seashore. Your offspring will possess the gate of his enemies. 18 All the nations of the earth will be blessed by your offspring, because you have obeyed my voice.’ ”
The apostle Paul confirms this idea to the Galatian believers:
7 Know therefore that those who are of faith are children of Abraham. 8 The Scripture, foreseeing that God would justify the Gentiles by faith, preached the Good News beforehand to Abraham, saying, “In you all the nations will be blessed.” 9 So then, those who are of faith are blessed with the faithful Abraham.
There are also many hints in the Old Testament that God always intended that individual salvation would be available to all:
1 Praise the LORD, all you nations!
Extol him, all you peoples!
2 For his loving kindness is great towards us.
The LORD’s faithfulness endures forever.
Praise the LORD!
The apostle Paul says that it is his mission to preach salvation to all:
16 For I am not ashamed of the Good News of Christ, because it is the power of God for salvation for everyone who believes, for the Jew first, and also for the Greek.