"The sweat of blood has central significance here. It is by no means just a device invented by St Luke to increase the melodrama of Jesus' agony. It has in fact been medically recorded occasionally in other people's situations of extreme horror. For instance, when a mother saw her child being crushed in front of her by a bus.
This shows that the sweating of blood was not out of anxiety towards his impending death, but like the mother's as she saw her son get killed- due to the anguish and horrible experience of visioning the panorama of humanity's sins across time.
Jesus sees the totality of our race, individually and socially, and the appalling damage we have done to ourselves and to others, and to God's plan of love.
He sees the horror our sins have caused and the suffering we have experienced because of them.
The sheer horror and dread of this experience causes his human nature to react with such sorrow, so deep a pain that we cannot fathom it.
In that vision he loves each one of us despite what we are and apologises from each of us to teh father. We are his chalice. His drinking of it is our redemption."