Question: : Where does it discuss how Satan was cast out of heaven? I have heard that two thirds of God’s angels that were loyal to Him were cast out with the devil but where is that in the Bible?
Answer: Revelation 12 is the source for this idea. You need to understand before we go much further in answering this question that there are several views of Revelation. Some view it as a record of things that had already occurred when John wrote them. Others see them as events played out over the course of church history. My view is that this book is meant to depict future events just prior to the coming of Christ’s kingdom to earth.
In my view, it is crucial to consider the often mentioned time marker of three and a half years. It is also referred to as “time, times, and half a time” and “42 months” and “1260 days” (see 11:2,3 and 12:14 as examples). Though the description of Satan as the “red dragon with seven heads and ten horns and seven crowns” who sweeps a “third of the stars out of the sky” could refer to Satan’s original rebellion before earth’s creation (the “stars” are interpreted by some as angels who rebelled with him), the description of his war with Michael the archangel and his subsequent loss and expulsion from heaven (vv.7-9) seems to take place in the future.
I say this because after Satan is hurled to earth a voice from heaven announces the soon coming of the kingdom of God and His Christ and that Satan is “filled with fury, because he knows that his time is short” (v.12). He pursues the woman (Israel) but she is cared for “a time, times and half a time,” that is, three and a half years, the time of the Great Tribulation. This is determined by a comparison with Daniel 9 and his prophecy of the 70 sevens, the king who makes a covenant with Israel for seven years then breaks it in the middle of that period (three and a half years in) and desecrates the temple by setting himself up for worship there.
All indications are that up until this time, even right now, Satan has access to heaven where he “accuses” us before God “day and night” (v.10; and see Job). Of course, Jesus intercedes for us so Satan’s accusations are baseless and futile.
So, Satan has not yet been cast out of heaven, is still considered the “prince of the power of the air” (Ephesians 2:2) and leads a band of fellow angels (Revelation 12:7, perhaps one third, not two thirds, of the angels created by God) who are at war with God. His doom is certain, but he continues foolishly to battle on.