15 And God said moreover unto Moses, Thus shalt thou say unto the children of Israel, The Lord God of your fathers, the God of Abraham, the God of Isaac, and the God of Jacob, hath sent me unto you: this is my name for ever, and this is my memorial unto all generations.
God had already identified Himself as “I AM THAT I AM,” and now He provides a second identification. He tells Moses to say that He is the God of Abraham, Isaac, and Jacob. These two definitions seem to be God going from who He is broadly (one who is self-defined), to who He is specifically to this world (the God who has established His covenant with the patriarchs).
He says that this description of Himself as the God of Abraham, Isaac, and Jacob will be His name forever. I don’t often hear God spoken of this way in today’s society, though. We know that Christ came to fulfill the law of Moses and prepare the gospel for all the non-Israelite gentiles, now it is available to all people, even those who are not direct descendants of Abraham. So why would God’s connection to the patriarchs still be a quintessential identifier even today?
For an answer I would refer to Galatians 3 and 4, where it is explained that all those who come into Christ are made part of God’s covenant by being adopted into the Abrahamic family. The significance of the patriarchs truly never was rescinded, not even with the spreading of the gospel to the gentiles. God still is the God of the chosen people, the only thing that changed is that all of us can be adopted into that family now. Thus it is accurate and appropriate for us to still identify God as the God of Abraham, Isaac, and Jacob, and to identify ourselves as being part of their descendancy.