And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels,
And prevailed not; neither was their place found any more in heaven.
And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him [Rev. 12:7–9].

And there arose war in heaven, Michael and his angels going forth to war with the dragon. And the dragon warred and his angels, and they prevailed not, neither was their place found any more in heaven. And the great dragon was cast down, the old serpent, the one called (the) Devil, and the Satan, he that deceiveth the whole (inhabited) world; he was cast down to the earth, and his angels with him were cast down.

We have here a startling revelation: “And there arose war in heaven.” The United Nations could not do anything about this war any more than they could about any other war that has taken place since they came into existence. It is difficult to imagine that there is war in heaven, but Satan still has access to heaven and, as long as he does, there will be this problem.
We are told in the Book of Job that Satan came with the sons of God to appear before God (see Job 1–2). He apparently had as much right there as they did. He had been created the highest creation. We also read in Zechariah 3:1–2: “And he shewed me Joshua the high priest standing before the angel of the LORD, and Satan standing at his right hand to resist him. And the LORD said unto Satan, the LORD rebuke thee, O Satan; even the LORD that hath chosen Jerusalem rebuke thee: is not this a brand plucked out of the fire?” Satan has access to God, and he is able to carry on a communication with God. Luke 22:31 tells us: “And the Lord said, Simon, Simon, behold, Satan hath desired to have you, that he may sift you as wheat.” I do not think that Satan sent a Western Union telegram to God or that he telephoned Him. He was able to come into the presence of God, and he requested that he might test this man Simon Peter—and he was granted that permission.
“Michael” is the archangel. We are told this in the Book of Jude: “Yet Michael the archangel, when contending with the devil he disputed about the body of Moses, durst not bring against him a railing accusation, but said, The Lord rebuke thee” (Jude 9). Evidently there are other archangels, but Michael has a peculiar ministry with the nation Israel. Daniel 10:13 tells us: “But the prince of the kingdom of Persia withstood me one and twenty days: but, lo, Michael, one of the chief princes, came to help me; and I remained there with the kings of Persia.” Michael is “one of the chief princes.” Although there are probably other archangels, Michael and Gabriel are the only ones whose names are given in Scripture. Again in Daniel we read: “But I will shew thee that which is noted in the scripture of truth: and there is none that holdeth with me in these things, but Michael your prince” (Dan. 10:21).
“Michael your prince”—since the Lord is talking to Daniel, this refers to Daniel’s people, the nation Israel. This is made clear in Daniel 12:1: “And at that time shall Michael stand up, the great prince which standeth for the children of thy people: and there shall be a time of trouble, such as never was since there was a nation even to that same time: and at that time thy people shall be delivered, every one that shall be found written in the book.” At that time, we are told, there will be a time of trouble, the Great Tribulation. Michael will again step out and drive Satan out of heaven, because he happens to be the prince who watches over the nation Israel. This is a tremendous thing, and it beggars description.
There will be a fierce struggle, a war. Satan is not going to retire easily, but Michael and his angels will prevail, and Satan and his angels will be thrown out of heaven. The Lord Jesus referred to this in Luke 10:18, “And he said unto them, I beheld Satan as lightning fall from heaven.”
There is no mistaking this creature who is called the great dragon, for he is marked out with great detail. His fingerprints are put down here in the Revelation. Because God knew that a great percentage of the preachers of this century would teach that Satan does not exist, He makes it so you cannot miss him. If your enemy can get you to think he does not exist, he will have a tremendous advantage over you, and he will be able to get a crack at you that will sweep you off your feet. Satan moved in afresh and anew during my generation simply because my generation did not believe in him. Now we are getting an overdose of him, and he has been made a weird and wild thing. But, actually, he is not an ugly creature, by any means; he is an angel of light,
Notice how he is identified here:
1. He is called “the old serpent.” This takes us back to the Garden of Eden. Our Lord said, “… He was a murderer from the beginning …” (John 8:44). The words old and beginning are akin, according to Vincent. Satan is that old serpent, the one who was at the beginning in the Garden of Eden.
2. He is called “Devil,” a name which comes from the Greek diabolos, meaning “slanderer or accuser.” He is so labeled in verse 10: “the accuser of our brethren.” This is the reason believers need an Advocate with the Father. You and I have an enemy today who is not only causing us problems down here, but you would be surprised what he says about you and me in heaven! There is nothing that you do or say or think which he does not turn in against you up yonder. But God already knows about it, and I like to beat Satan to the draw and confess it before he gets up there to bring the accusation against me. The Lord Jesus is our Advocate. “My little children, these things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous” (1 John 2:1).
It would be wonderful if I did not sin, but I do. Thank God that we have an Advocate with the Father. Jesus Christ the righteous is up there to defend us. He has been kept busy ever since I have been in this world, and I have a notion He’s been pretty busy defending you, too. Don’t think He is up there sitting idly by. He is our Defender, our Advocate. The Devil is a slanderer; he is a liar from the beginning. He is the origin of all lies today. Where does the gossip that goes on in some of our churches originate? It originates in the pit of hell, my friend. That is the last place from which anything ought to be shipped into the church!
3. He is also called “Satan,” which means “adversary.” He is the awful adversary of God and of every one of God’s children. We are told: “Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour” (1 Pet. 5:8). I have received a great many letters from people who have been delivered out of cults and “isms” through the study of the Word of God. One man wrote: “I was in a cult. I wrote you the letter I did [and it was a mean one!] to try to trap you, to try to trick you. I thought I was right and you were wrong. When I began to study the Word of God, I came to realize how Satan had me trapped.” Satan has a lot of folk trapped today, even church members. We need to recognize that he is our enemy. That does not mean we ought to go overboard and just dwell on Satan and demons. It certainly is true that there is a new and fresh manifestation of him today that was not here a generation ago. But keep your eye on Jesus Christ, for He is your place of deliverance, and He is up yonder to help you.
4. Finally, he is called “he that deceiveth the whole (inhabited) world.” During the Great Tribulation, Satan will be able to totally deceive men—today he deceives only partially. Satan deceives men relative to God and the Word of God. He caused Eve to distrust God: “Has God said you should not eat of that tree? You just can’t trust Him, can you?”(see Gen. 3:1–4). Satan deceives man relative to man. Satan makes out mankind better than he is, yet he despises us. He builds us up and tells us we could become gods—how wonderful that would be (see Gen. 3:5). Satan deceives man relative to the world, the flesh, and the Devil. You and I think we are big enough to overcome the world, the flesh, and the Devil, but we are not big enough to overcome any one of them. The world is too big for us, and it will certainly draw us away from the Lord. Satan deceives man relative to the gospel. He does not mind a man going to church or even joining a dozen churches, but he does not want that man to be saved. “In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them” (2 Cor. 4:4).
Someone has said, “Satan is to be dreaded as a lion; more to be dreaded as a serpent; and most to be dreaded as an angel.” That is where he traps multitudes today. McGee, J. V. (1997). Thru the Bible commentary (electronic ed., Vol. 5, pp. 990–992). Nashville: Thomas Nelson.

Re 12:7 war broke out in heaven. The tumultuous events on earth during the Tribulation find their counterpart in heaven. A state of war has existed since the fall of Satan (cf. v. 4; cf. Dan. 10:13; Jude 9). Something will intensify that warfare—possibly the raptured saints passing through the realm of the prince of the power of the air (cf. Eph. 2:2).
12:9 dragon was cast … to the earth. Satan and his demons were cast out of heaven at the time of their original rebellion, but still have access to it (cf. Job 1:6; 2:1). That access will then be denied, and they will be forever barred from heaven. Devil and Satan. Cf. 20:2. “Devil” comes from a Gr. verb meaning “to slander” or “to falsely accuse.” He is a malignant liar (John 8:44; 1 John 3:8). His accusations against believers (v. 10) are unsuccessful because of Christ our Advocate (1 John 2:1). Satan, meaning “adversary,” or “enemy,” appears especially in Job and the gospels. deceives the whole world. As he has throughout human history, Satan will deceive people during the Tribulation (cf. 13:14; 20:3; John 8:44). After his temporary release from the bottomless pit at the end of the Millennium, he will briefly resume his deceitful ways (20:8, 10). MacArthur, J., Jr. (Ed.). (1997). The MacArthur Study Bible (electronic ed., p. 2008). Nashville, TN: Word Pub.