It is a hard thing to be forsaken by a bad father, hard enough that it breaks some lives. Outside observers might say "good riddance," but for the abandoned one there is still pain.
How much more to be abandoned by a good father. I thought not only of the Son's separation from the Father, but the Father's from the Son. This is the father that ran to meet the prodigal son. This is the father who kept reaching out to Israel to bring her back. This is the father Jesus turned to when his earthly family rejected him and wanted to put him away. This is the father he went to when he was tired, hungry to the point of starving, frustrated with a nation and even close disciples who did not get it.
I think of myself promising my children that if you are ever pulled away from me somehow I will not rest until I find you. You can count on that in any darkness, that I am thinking about you every moment and will not stop looking for you. I don't even like thinking of the possible plotlines where a parent has to act on that (though some have had the horror of living through such things). I
He had never been turned away before. Perhaps there was some not fully conscious thought in Gethsemane that "this will be hard, impossibly hard, not only physically but spiritually, but I can make it because you are with me." And then suddenly at the very end the realisation I will go into the darkness alone. The one who has always been there will not be there.