Reprobation and the Line of the Covenant

I have been asked to write on the idea of the covenant being two sided that is that the decree of reprobation cuts through the line of the covenant. In response to this request I would like to treat the topic from the point of view of the Word of God that we read in Romans 9: 9 and its context. In Romans 9: 6-9 we read, “Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel: Neither, because they are the seed of Abraham, are they all children:...