John 12:39

Verse 39. They could not believe, [3] that is, they would not, says Saint Augustine or it could not be, considering their wilful obstinate blindness. Witham.—But where then is the sin, if they could not believe? They could not believe, because they would not. For as it is the glory of the will of God, that it cannot be averse to its own glory, so it is the fault of the will of man, that it cannot believe. Saint Augustine tract. 53. in Joan. They could not believe. Since the prophet has foretold it, and he cannot but say the truth, it is impossible that they should now believe. Not but they had it in their power to believe; and had they believed, the prophet would never have foretold the contrary. Saint John Chrysostom hom. lxvii in Joan.