It seems as if the word of God has failed, says Rom 9, because there is all the unbelief of Israel. But it has not failed. The promises never were for the race all the way through time. If they were, then Rom 9 would answer with a list of prophecy yet to be fulfilled. Instead, its answer is the exceptions to all the race (including Isaac), and the fact of the Gentiles who believe as part of "us" "the objects of mercy" "the elect" "the remnant."