John Chrysostom
Catena Aurea · Johannesevangelium 3
For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. For God sent not his Son into the world to condemn the world; but that the world through him might be saved. He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
(Hom. xxviii. 1) Or the meaning is, that disbelief itself is the punishment of the impenitent: inasmuch as that is to be without light, and to be without light is of itself the greatest punishment. Or He is announcing what is to be. Though a murderer be not yet sentenced by the Judge, still his crime has already condemned him. In like manner he who believes not, is dead, even as Adam, on the day that he ate of the tree, died.