Saving a People as an 'Aside'

John MacArthur's comments on all good Calvinists being pre-millennial has got me thinking again. But I definitely don't agree.

Historic Dispensationalism stated outright that God's plan to save the Gentiles now--in an age of grace--is an aside from God's plans to save Israel and establish them as God's people. Contemporary Dispensationalism, of course, would never use such crass terms, but to put forward the notion that God will return somehow to dealing with one nation again, after giving his gospel--which is the fulfilment of all the revelation given to Israel, and which is given in order to bring about the obedience of the nations--really is to suggest the same thing in perhaps more friendly terms.

I would suggest, however, that a simple reading of Galatians and Paul's view of redemptive-history given there would suggest otherwise. From Adam to Abraham, God dealt with the nations. From Abraham on God dealt primarily with Abraham's seed--a particular people group--but this seed was specifically prophesied as the one who will bring God's blessing to all nations.

A little while later, God continues to deal with Israel alone and gives the Law, which they must obey; this Law is the standard by which they must live and be judged, it is what makes Israel distinct as God's people. This Law, however, as Paul says, is fulfilled (as are the promises to Abraham) in Christ.

Why in the world, then, would we expect for God to go back to dealing with one nation alone? Wouldn't that be to reverse of the working out of his plan in salvation-history?

Though I would never put it in these terms (tongue planted firmly in cheek), if we must view the saving of a particular people in salvation-history as an 'aside', wouldn't it be Israel? If God's original plan with Adam and then subsequently with Abraham (and I think it could be easily shown through Israel as well) is for 'the whole world', then why would he go back to dealing specifically with a covenant-people whose covenant has been rendered obsolete?