How can God say all nations will be blessed if He is dealing only with Israel?
God can promise blessing to all nations because Israel is the channel through which His Word and blessing flow. As Paul explains, the Jews were entrusted with the oracles of God, and every Scripture writer came from Israel. Through Abraham's seed, the blessing extends to all nations, while Israel remains the conduit.
Les explains that the Abrahamic Covenant promises, 'in thee shall all nations of the earth be blessed.' The question arises: how can God say nations if He is dealing with Israel? Les answers by showing that everything must come through this one little nation. Every word of the Book came out of the nation of Israel; all the writers of Scripture were Jews, as Paul makes plain in Romans chapter 3. There Paul asks, 'What advantage then hath the Jew?' and answers, 'Much in every way, but especially or chiefly, that unto them were committed the oracles or the word of God.' This makes the Book totally unique from any other religious book. So the blessing to all nations comes through Abraham's seed because Abraham obeyed God's voice, kept His charge, commandments, statutes, and laws. Les then moves to chapter 46 to deal with Jacob as the next in the line.
And I will make thy seed to multiply as the stars of heaven, and will give unto thy seed all these countries; and in thy seed shall all the nations of the earth be blessed;
More Questions
Why does God say all nations in a promise He made to Israel?
God's promise to Israel can mention 'nations' because every blessing for the nations has to come through the nation of Israel.