Perhaps, as a way of establishing a foundation on which to discuss the promise God made to Abraham, which of course would be unbreakable, one could ask a question of all. The question is this: Is the promise made to Abraham in Genesis 12:1-3 the same promise as that made to Eve in Genesis 3:15, albeit with greater detail? If some on this thread consider the two promises to be different, how are they materially different from each other? I do not see how any profitable discussion can go forward without resolving this simple but important question.
I'd say the promise made to Eve in Genesis 3:15 refers to Christ's coming. The promise made to Abraham in Genesis 12:1-3 advances the plan of God as pertains to Christ Jesus - and thusly, to our salvation through faith, just as the promise to Abraham was given by his faith that God was able to raise the dead.