John 6:64-66

Verse 64

But there are some of you that believe not - This is addressed to Judas, and to those disciples who left him: Joh 6:66.

And who should betray him - Or, who would deliver him up. Because he knew all things; he knew from the first, from Judas's call to the apostleship, and from eternity, (if the reader pleases), who it was who would (not should) deliver him up into the hands of the Jews. Should, in the apprehension of most, implies necessity and compulsion; would implies that he was under the influence of his own free will, without necessity or constraint. The former takes away his guilt: for what a man is irresistibly compelled to do, by the supreme authority of God, he cannot avoid; and therefore to him no blame can attach: but Judas having acted through his own free will, abusing his power, and the grace he had received, he was guilty of the murder of an innocent man, and deserved the perdition to which he went.
Verse 65

Therefore said I unto you - Joh 6:44. See the note there.

Except it were given unto him - None can come at first, unless he be drawn by the Father; and none can continue, unless he continue under those sacred influences which God gives only to those who do not receive his first graces in vain. St. Augustin himself grants that it was the sole fault of these disciples that they did not believe, and were saved. Quare non Poterant credere, si a me quaeratur, cito respondeo, quia Nolebant. If I be asked why these could not believe, I immediately answer, because they Would Not. Aug. Tract. 53, in Joan.
Verse 66

Many of his disciples went back - They no longer associated with him, nor professed to acknowledge him as the Messiah. None of these were of the twelve. Christ had many others who generally attended his ministry, and acknowledged him for the Messiah.
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