John 3:15 - Ellicott's Commentary On The Whole Bible

Not perish, but... — These words have been added here from the following verse. Omitting them, the sentence should be rendered, that every one who believeth may have in Him eternal life. This construction is borne out by a comparison of John 5:39; John 16:33; John 20:31. “To believe in Him” is not used by St. John. (See Note on John 1:12.) The thought of this verse is that as every Israelite, believing in God, had in the brazen serpent a message from God; so every man who believes in God ever has this message from God in the crucified Son of Man. The object of faith is not here expressed. The words speak only of the man who believeth, whose heart is open to spiritual truth. That man has, in Jesus Christ and Him crucified, a truth which goes to his inmost spirit, sending a new life through his whole being. To the non-believer this may be but the self-sacrifice of heroism. To the believer it is Light breaking upon the darkness of his soul; it is Life bursting the cold sepulchre of a deadened spirit; it is Love winning its way through the scales of a hardened heart; it is Mercy deeper and wider even than his sin; it is Hope bracing the man to a new life of holiness; it is the Word of God, and in Him he has eternal life. The reader will not forget that the lifting up the serpent of brass followed the confession of the people. “We have sinned... pray unto the Lord that He take away the serpents from us” (Numbers 21:7).