So when Paul reminds his hearers, who are familiar with the story of Abraham, that the promise did not come to Abraham because of his adherence to the covenant marker that would eventually be designated under the heading “works of the law” (which came later), and that Abraham received his righteousness (standing inside the covenant, justification, salvation, right standing with God---all of which comes with responsibilities for this life and in this world, having little if nothing to do with the destination of one’s eternal soul and whether or not one ends up in heaven or hell) through faith, he is not juxtaposing works and faith in relation to justification. Rather, his focus remains on covenant markers and legitimating Gentile inclusion, with the latter being an obvious part of God’s plan from the very beginning.
It seems clear that Paul recognizes, in Jesus, at least a partial (if not complete) fulfillment of God’s promises to Abraham, so the spreading of the Gospel message (Jesus is Lord) to the Gentile world, with the subsequent submission to that message and to the Lord of the message, is a very natural progression. Accordingly, this fits very well with, and makes much sense of the words of the prophets of old that are very obviously world-encompassing.
With verse fourteen, Paul points up the inherent conflict involved in ascribing justifying activity to adherence to covenant markers (thus contributing to the possibility of a mental blurring of lines that we mentioned before), when he writes “For if they become heirs by the law, faith is empty and the promise is nullified” (4:14). Again, covenant membership (justification, salvation) does not and cannot come from the covenant markers. The markers are reminders of belief. Importantly, God has not changed His mind (we can relieve Him of the charge of schizophrenia when it comes to His plans for His world and His people). The example of Abraham proves this. He was in covenant because of belief. If this is not so, and if he was not actually in covenant until the event of his circumcision, then belief is indeed empty, for it produced nothing. The promises made to him then, all of which came before his circumcision and from the very beginning point to the global people of God that become His people through the same means employed by Abraham (faith), are null and void.
Though Abraham obviously is not in a position to confess Jesus as Lord, we see the story of his life as his confession, reflecting His unswerving loyalty to the God of the promise. Those of us now in the position to confess Jesus as Lord should similarly seek that the story of our lives be the silent confession of the same unswerving loyalty, generating the opportunity to offer verbal, public declaration.
Belief is transcendent. It transcends the works of the law. It does not stand over and against the works of the law that were but reminders of a previous covenant shaped by previous faithfulness and a faithful response, but rather serves as the foundation. To make this point, Paul adds that “it is by faith so that it may be by grace” (4:16a). Grace, of course, was present in God’s dealings with Abraham, and did not receive its advent with that of Jesus. Thus it has “the result that the promise may be certain to all the descendants---not only to those who are under the law” (4:16b), the Jews, “but also to those who have the faith of Abraham” (4:16c), who are all those that enter into covenant (including those who have the law) by means of their belief in the God of the covenant.
In conjunction with these moves, Paul makes a point to here reiterate that Abraham, “is the father of us all” (4:16d). In a culture that places a heavy emphasis on the father as the head of a household and the honor of that position, whether that culture be Jew or Gentile, with much additional honor (for the Jew) attached to being a member of Abraham’s household, this is not an insignificant statement. The household could extend beyond blood relations, which we see in the story of Abraham, as he is willing to look to a servant in his house as a completely legitimate heir to the covenantal promise, and would have considered God’s carrying on and carrying out of His promise through that servant as a demonstration of His covenantal faithfulness. This would not necessarily be an unusual position for Abraham to take, as it was a common and accepted practice for a favored servant to enjoy benefits in line with being a biological or adopted son. Therefore, this particular use of the Abraham example is doubly emphatic when applied to the status of Gentiles in relation to the covenant (not to mention the whole of the believing community), in that there is an egalitarianism insistence, in that all that come to belief in Jesus are of the same family and bear the same status, while it also joins Jew and Gentile together in a mythic physical descent, as Paul adds “(as it is written, ‘I have made you the father of many nations’)” (4:17a).