John Lightfoot on John 16:11

[Of judgment, because the prince, &c.] It is well known that the prince of this world was judged when our Saviour overcame him by the obedience of his death, Hebrews 2:14: and the first instance of that judgment and victory was when he arose from the dead: the next was when he loosed the Gentiles out of the chains and bondage of Satan by the gospel, and bound him himself, Revelation 20:1,2: which place will be a very good comment upon this passage.

And both do plainly enough evince that Christ will be capable of judging the whole world, viz. all those that believe not on him, when he hath already judged the prince of this world. This may call to mind the Jewish opinion concerning the judgment that should be exercised under the Messiah, that he should not judge Israel at all, but the Gentiles only; nay, that the Jews were themselves rather to judge the Gentiles, than that they were to be judged. But he that hath judged the prince of this world, the author of all unbelief, will also judge every unbeliever too.