NOTES for Joh 8:39-40
The Jews always considered themselves children, descendants, of Abraham, and this is an unquestionable historical fact. In every age this fact was enough for every Jew to consider himself belonging to the people of God. But then the Messiah comes and poses the question differently.
It turns out that it is not enough to be Abraham's descendant by blood; one must also be his heir in spirit. And that is more difficult. Indeed, what did Abraham do? He followed God, who called him. But what did this mean for him? Abraham knew nothing about the God who had called him; for him the God of Israel was still an unknown God. Abraham came to know Him already on the way to Palestine and later in Palestine itself. At first he simply had to entrust himself to the One he did not know, to believe at the first meeting. Of course, Abraham heard God's voice, but in those days hearing the voice of some god or spirit was not such a rarity.
There were many gods and spirits, and there were many voices too; but whom to trust was something each person decided for himself. The voice that called Abraham after itself was the voice of the Unknown. This voice promised much, but could it be trusted? Abraham believed. His heart told him that the Unknown One was not deceiving him. In this he is the complete opposite of those deeply religious but very distrustful Pharisees who constantly demanded proof from Jesus of His messiahship, and moreover proof that would correspond to their own ideas about the Messiah.
If Abraham had been like that, there would have been no Jewish people, simply because such an Abraham would never have believed the unknown God. And of course, with the openness that was characteristic of Abraham, he would never have begun to persecute, much less try to kill, a person who was attempting to tell him something new about his God. This is what distinguishes Abraham from those who turned out to be his descendants by blood but not by spirit. Abraham had every opportunity to enter the Kingdom. But his descendants had serious problems with this. Not all of them, of course, but many. Especially those who considered themselves completely ready both for the meeting with the Messiah and for the Kingdom.