John 12:31

Now … now With prophetic certainty Christ speaks of the victory as already won.

the judgment of this world The sentence passed on this world (see on John 3:17 and John 5:29) for refusing to believe. The Cross is the condemnation of all who reject it.

the prince of this world Literally, the ruler of this world. This is one of the apparently Gnostic phrases which may have contributed to render this Gospel suspicious in the eyes of the Alogi (see Introduction, Chap. II. i): it occurs again John 14:30; John 16:11, and nowhere else. It was a Gnostic view that the creator and ruler of the material universe was an evil being. But in the Rabbinical writings -prince of this world" was a common designation of Satan, as ruler of the Gentiles, in opposition to God, the Head of the Jewish theocracy. But just as the Messiah is the Saviour of the believing world, whether Jew or Gentile, so Satan is the ruler of the unbelieving world, whether Gentile or Jew.

shall … be cast out By the gradual conversion of unbelievers. This is a process which will continue until the last day.