John the Apostle
John 3:18ESV·traditional attribution

Whoever believes in him is not condemned, but whoever does not believe is condemned already, because he has not believed in the name of the only Son of God.

John Calvin Reformed @genevareformer

18. He who believeth in him is not condemned. When he so frequently and so earnestly repeats, that all believers are beyond danger of death, we may infer from it the great necessity of firm and assured confidence, that the conscience may not be kept perpetually in a state of trembling and alarm.

Matthew Henry Presbyterian @wholebiblehenry

We found, in the close of the foregoing chapter, that few were brought to Christ at Jerusalem; yet here was one, a considerable one. It is worth while to go a great way for the salvation though but of one soul. Observe, I. Who this Nicodemus was. Not many mighty and noble are called; yet some are, and here was one.

Commenting on John 3:1-21

John Gill Reformed Baptist @doctorgill

And this is the condemnation,.... Of him that believes not in Christ; that is, this is the matter and cause of his condemnation, and by which it is aggravated, and appears to be just: that light is come into the world: by which is meant, not natural or corporeal light; though natural darkness is, by some, preferred to this, being more convenient for their evil...