A.T. Robertson Commentary Revelation 12:7

"And there was war in heaven: Michael and his angels [going forth] to war with the dragon; and the dragon warred and his angels;" — Revelation 12:7 (ASV)

There was war in heaven (εγενετο πολεμος εν τω ουρανω). "There came to be war in heaven" (εγενετο, not ην). "Another ταβλεαυ, not a σημειον (vv. 1,3), but consequent upon the two σημεια which precede it. The birth and rapture of the Woman's Son issue in a war which invades the επουρανια" (Swete). The reference is not to the original rebellion of Satan, as Andreas held. As the coming of Christ brought on fresh manifestations of diabolic power (Luke 22:3,31; John 12:31; John 14:30; John 16:11), just so Christ's return to heaven is pictured as being the occasion of renewed attacks there. We are not to visualize it too literally, but certainly modern airplanes help us to grasp the notion of battles in the sky even more than the phalanxes of storm-clouds (Swete). John even describes this last conflict as in heaven itself. Cf. Luke 10:18; 1 Kings 22:1ff.; Job 1; 2; Zechariah 3:1f..

Michael and his angels (ο Μιχαηλ κα ο αγγελο αυτου). The nominative here may be in apposition with πολεμος, but it is an abnormal construction with no verb, though εγενετο (arose) can be understood as repeated. Michael is the champion of the Jewish people (Daniel 10:13,21; 12:1) and is called the archangel in Jude 9.

Going forth to war (του πολεμησα). This genitive articular infinitive is another grammatical problem in this sentence. If εγενετο (arose) is repeated as above, then we have the infinitive for purpose, a common enough idiom. Otherwise it is anomalous, not even like Ac 10:25.

With the dragon (μετα του δρακοντος). On the use of μετα with πολεμεω see 2:16; 13:4; 17:14 (nowhere else in N.T.). The devil has angels under his command (Matthew 25:41) and preachers also (2 Corinthians 11:14f.).

Warred (επολεμησεν). Constative aorist active indicative of πολεμεω, picturing the whole battle in one glimpse.