John 3:14,15 - Joseph Benson’s Commentary on the Old and New Testaments

As Moses lifted up the serpent As if he had said, And even this single witness, bearing testimony of heavenly things, will soon be taken from you; yea, and in a most ignominious manner. Or, as Dr. Doddridge connects the words with what precedes, “And now I mention the Son of man, let me rectify that grand mistake of yours concerning his kingdom, which otherwise may be attended with fatal consequences. You expect to see him raised on a magnificent throne; and not only breaking off the yoke from the Jewish nation, but leading them on to conquer and destroy the Gentiles; but I must assure you that, as Moses lifted up, [Greek, υψωσε, raised on high, namely, on a pole,] the serpent in the wilderness To heal those that were dying by the venom of the fiery serpents there; even so must the Son of man be lifted up On a cross, (see the margin,) and then publicly exhibited in the preaching of the gospel, that sinners may by him receive a far more noble and important cure; even that whosoever believeth in him should not perish As all in their natural state otherwise would; but may obtain so perfect a recovery as certainly to have eternal life” For all those who look to him, and rely on him by faith, recover spiritual life and health. The reader will observe, 1st, That the grand point of similitude here is, in the manner of performing the cure, that is, by believing regards to what was lifted up, or raised on high, for that purpose, by a divine appointment. 2d, That the passage strongly implies, that as the wounded Israelites would have died if they had not looked to the brazen serpent for a cure, so will men, wounded by sin, original and actual, assuredly perish, and that eternally, if they do not look to, and believe on Christ, delivered unto death for their offences, and raised from the dead for their justification; which great truth is still more strongly expressed, John 3:18. 3d, That our Lord, by telling Nicodemus, that the death of the Messiah was prefigured by types in the law, showed him, that it was agreeable both to the doctrine of Moses, and to the counsels of heaven, that the Messiah should be in a suffering state; and consequently he intimated that the meanness of his present appearance on earth was no reason why any should doubt of his having been, and still being in heaven.