Hovey:

16. For God so loved the world, etc. This verse has been called an epitome of the whole gospel, and no single statement of the New Testament is better entitled, to this designation. (1) It goes back of the whole work of redemption, and reveals the motive in which that work had its origin. (2) It describes that motive as love or good-will, not merely to the chosen people, or to the elect from every nation, but to all mankind; for this is the only tenable meaning of the world, as here used. (3) It pronounces the gift of Christ, with the work implied in that gift, a sufficient reason for the salvation of every man who will believe in him. And (4) it presents that salvation to the mind as eternal life, or, in other words, a blessed state of being begun on earth and continued forever. On the other hand, it may be said to imply (a.) that, without the work of Christ, men could not have had eternal life, and (b) that, without faith in him, they cannot now have eternal life, although he has been lifted up on the cross. The adverb so means, with so great a love, and the verb gave has respect to all the humiliation and suffering which he endured for men, and which culminated on Calvary. (See Rom. 8: 32.)

17. For God sent not his Son into the world to condemn the world, etc. The word translated condemn, literally signifies to judge; but generally, in this Gospel, with an implication that the decision is unfavorable. Hence it is not improperly rendered condemn. The Jews are said to have expected a Messiah who should judge and punish the Gentile world, and the language here used may be directed against this error. But it can hardly be supposed that this was the principal reason for these words. They have a larger scope. They apply to all men–Jews as well as Gentiles. In so far as men are concerned, the object of the Father in sending the Son was to furnish them the means of salvation. They were already judged and condemned as sinners; but the Father had purposes of mercy, and sent his Son to open a way of escape to those under condemnation. Yet it was a provision which recognized the moral agency of man. The sending of the Son did not, in and of itself, save the world; hut it was necessary, in order that the world might be saved, if it would. These two verses (16 and 17) give the motive and purpose of the incarnation. The result of it is next pointed out.

Alvah Hovey, Commentary on the Gospel of John (Philadelphia: American Baptist Publication Society, 1885), 101-102. [Underlining mine.]