Then many of his disciples hearing this said 'This saying is hard to take. Who can understand this?'

Jesus, knowing in himself that his disciples were grumbling because of this, said to them:
'Does this cause you to stumble?
So what if you see the Son of Man going up to where he was before?
It is the Spirit who gives life; the flesh achieves nothing.
The words which I have spoken to you are spirit and are life.
But among you are some who do not believe.

(For in fact Jesus knew from the beginning some were unbelievers and as well as who would betray him.)

And he went on to say 'This is why I have said "Nobody can come to me unless the Father has granted it to them."'

Lord, you have given me so much,
I ask for one more thing -
a grateful heart.

George Herbert