"God reigns over the nations; God sits on His holy throne. The princes of the people have gathered together; the people of the God of Abraham. For the shields of the earth belong to God; He is greatly to be exalted" (Psalm 47:8-9).
There is a common belief among evangelicals that only the church is accountable to God. In fact, dispensationalists would go even further and claim that only Israel is accountable to God, as a nation. But those assumptions are based on human presuppositions, not on any assertion of Scripture.
Notice the verses above, in which the Psalmist tells us that God reigns, not over Israel, but explicitly over the "nations," which can also be translated as "Gentiles." When God created Adam, He created the founder of the human race, not of the people of Israel in particular. That is the establishment of His universal rule over all of mankind, of whatever nation we may be.
The mistake that the dispensationalists make is that they overlook the role that Israel fulfilled as the reestablishment of a people in faithful covenant with God. Adam and Eve and their immediate descendants in the line of Seth were in such a faithful covenant. Yet they died out, such that God called Abraham, a pagan, into His covenant of grace, to restore the line of faith among men. Abraham, too, was not a Jew; they were to be his descendants.
That is why Paul could refer to the Gentiles called by God's name, because this was not a new concept, contrary to the assertions of dispensationalists, but a return to God's original purpose, as described, not just in the psalm above, but also in Amos 9:11-12: "After this, I [God] will return and will rebuild the tabernacle of David, which has fallen down; I will rebuild its ruins, and I will set it up; so that the rest of mankind may seek the Lord, even all the Gentiles who are called by My name, says the Lord who does all these things" (in the Septuagint version, as quoted in Acts 15:16-17).
After the Fall, the focus of God's revelation narrowed step by step to just one man, Abraham. From him, that revelation began to widen again step by step to its original scope, until it once again includes all elect men, whether Jewish or Gentile. Dispensationalists err when they try to distinguish between the Jews as the people of God and the Gentiles as a mere parenthesis in His plans of redemption.
