Is the 'War in Heaven' (from Revelation 12:7) a Past or Future Event?

Question from a reader:

I am reading If God is Good. On page 155, Randy implies that the 'war in Heaven' in Revelation 12:7 is past (he uses the word "accomplished"). This seems to jive with the words of Jesus in Luke 10:18 where He says He "saw Satan fall like lightning from heaven." Some writers place the Rev. 12:7 'war in Heaven' as yet in the future. Which is it? Past event or a future event?

Answer from Randy Alcorn:

Scripture often has an "already and not yet" aspect to it. We are already saved (delivered from penalty of sin), but we are being saved (delivered from power of sin) and will be saved in the future (delivered from the presence of sin).

Similarly, Satan has already been defeated (thrown out of heaven and defeated by Christ's atonement resurrection), he is being defeated (in a present battle described in Ephesians 6), and he will be defeated in the final battle. So the war in heaven has happened in the past, is happening now, and will happen in the future for the final time. So Rev. 12:7 has past, present and future implications all at once. It appears to me to be primarily a statement of what happened in the past when Satan in the first battle was kicked out of Heaven, but it will happen again in sort of a final battle that will end the war once and for all.  

Randy Alcorn (@randyalcorn) is the author of over sixty books and the founder and director of Eternal Perspective Ministries