Albert Barnes Commentary John 3:18

"He that believeth on him is not judged: he that believeth not hath been judged already, because he hath not believed on the name of the only begotten Son of God." — John 3:18 (ASV)

He that believeth. The one who has confidence in him, who relies on him, who trusts in his merits and promises for salvation. To believe in him is to feel and act according to truth—that is, to go as lost sinners and act toward him as a Savior from sins, relying on him and looking to him only for salvation. (See Barnes on Mark 16:16).

Is not condemned. God pardons sin and delivers us from deserved punishment because we believe in him. Jesus died in our place; he suffered for us, and by his sufferings our sins are expiated, and it is consistent for God to forgive. When a sinner, therefore, believes in Jesus, he trusts in him as having died in his place. God having accepted the offering which Christ made in our place, as being an equivalent for our sufferings in hell, there is now no further condemnation (Romans 8:1).

He that believeth not. All who do not believe, whether the gospel has come to them or not. All people by nature.

Is condemned already. By conscience, by law, and in the judgment of God. God disapproves of their character, and this feeling of disapproval, and the expression of it, is the condemnation. There is no condemnation so terrible as this—that God disapproves of our conduct, and that he will express his disapproval. He will judge according to truth, and woe to that person whose conduct God cannot approve.

Because. This word does not imply that the ground or reason for their condemnation is simply that they have not believed, or that they are condemned solely because they do not believe in him—for there are millions of sinners who have never heard of him. Rather, the meaning is this: There is only one way by which people can be freed from condemnation.

All people without the gospel are condemned. Those who do not believe are still under this condemnation, not having embraced the only way by which they can be delivered from it. The verse may be paraphrased as follows: "All people are by nature condemned. There is only one way of being delivered from this state—by believing in the Son of God. Those who do not believe, or who remain in that state, are still condemned, FOR they have not embraced the only way in which they can be freed from it."

Nevertheless, those to whom the gospel comes greatly heighten their guilt and condemnation by rejecting the offers of mercy and trampling under foot the blood of the Son of God (Luke 12:47; Matthew 11:23; Hebrews 10:29; Proverbs 1:24–30).

And there are thousands going to eternity under this double condemnation:

1. For positive, open sin; and,
2. For rejecting God's mercy and despising the gospel of his Son.

It is this that will make the doom of sinners in Christian lands so terrible.