Adam Clarke on John 3:17

For God sent not, etc. - It was the opinion of the Jews that the Gentiles, whom they often term the world, עלמה olmah, and אומות העולם omoth haolam, nations of the world, were to be destroyed in the days of the Messiah. Christ corrects this false opinion; and teaches here a contrary doctrine. God, by giving his Son, and publishing his design in giving him, shows that he purposes the salvation, not the destruction, of the world - the Gentile people: nevertheless, those who will not receive the salvation he had provided for them, whether Jews or Gentiles, must necessarily perish; for this plain reason, There is but one remedy, and they refuse to apply it.