The alternative to this view would be Reformed federal/covenant theology. Where history and humanity revolve around the first Adam and the last Adam, the Covenant of Works and the Covenant of Grace. The idea that there has always been only one way to be saved and his name id Chrsit Jesus: the OT saints looked forward to his coming by faith, and we look backward. God's dealings are not primarily with the Jews but with the fallen race as a whole (Gen. 3:15), and that the time of the Jews was a parenthetic in that greater story. This too is a very inadequate explanation given the space (and medium) but that's a trailhead for you to take if you want to pursue it further. You could, for example, read the Westminster Confession or the Larger Catechism or the Heidelberg to get at the "big picture" of what the whole counsel of God principally teaches.