And there was WAR in heaven,
Now this really goes against our preconceived idea of heaven being a peaceful place filled with beautiful music and so on, but there is WAR in heaven. This may well be a different kind of WAR than what we know here on earth. Spiritual warfare is soul and spirit related; two areas we are not but should be very familiar with.
This verse must be tied to the hymn in verse 10 and following. Thus the redemption by the Son's blood was fought over in heaven long before/or even til the earthly conflicts we have. Christ WINS THEM ALL!
Michael and his angels waging war with the dragon.
Michael is found five times in the Bible, and he always is associated with the protection of Israel:
From the reference to the 1,260 days in the previous verse, we know that this WAR must take place during or at the end of the tribulation period. The earthly saints have been translated into heaven and only the woman/man-child problem for the dragon remains. Recall the 'great sign' of the woman appeared IN HEAVEN.
And the dragon and his angels waged WAR.
This WAR was an all out conflict between 'stand ins': Michael (for Christ) and his angels vs. the dragon (for devil) and his angels. There was a direct one on one confrontation between Jesus and the devil recorded in Matthew 4:1-11 and Luke 4:1-13. The quotation of scripture was how these 'temptations' were overcome. This verse doesn't indicate if Michael and his angels use scripture to fight this WAR at this 'opportune time'.
Also compare this with 1 Kings 22:13-23 where a spiritual conflict was between ONE prophet, Micaiah verses many 'false prophets'. The conflict in this verse is much larger.