NOTES for Joh 8:39-40
The Jews have always considered themselves children, descendants, of Abraham, and this is an unquestionable historical fact. This fact was enough for every Jew in all times 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 successor in spirit. And this 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 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. But at the beginning he simply had to trust the One he did not know. To believe at the first meeting. Abraham, of course, heard the voice of God, but in those days to hear the voice of some god or spirit was not such a rarity.
There were many gods and spirits, and many voices too, but whom to trust was something each person decided for himself. The voice that called Abraham to follow 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. And in this he is the complete opposite of those deeply religious but very distrustful Pharisees who constantly demanded proofs from Jesus of His messiahship, and moreover proofs 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 kind of openness that characterized Abraham, he would never have persecuted, still less tried to kill, a person 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 possibility of entering the Kingdom. 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.