The following is an excerpt from The MacArthur New Testament Commentary on Revelation 12:10.

Then I heard a loud voice in heaven, saying, “Now the salvation, and the power, and the kingdom of our God and the authority of His Christ have come, for the accuser of our brethren has been thrown down, he who accuses them before our God day and night.” (Revelation 12:10)

The Bible exposes Satan’s devious and deceitful nature as the “father of lies” (John 8:44), cautioning that he “disguises himself as an angel of light” (2 Cor. 11:14; cf. 2 Cor. 11:3) so that he can more easily deceive people. The apostle Paul expressed his concern “that no advantage would be taken of us by Satan, for we are not ignorant of his schemes” (2 Cor. 2:11). “Put on the full armor of God,” the apostle urged the Ephesians, “so that you will be able to stand firm against the schemes of the devil” (Eph. 6:11).

One of the most pervasive and persistent popular myths about Satan pictures him (complete with pitchfork, horns, and pointed tail) as being in charge of hell. In reality, Satan is not in hell; in fact, he has never been there. He will not be sentenced to the lake of fire until after his final rebellion is crushed at the end of the Millennium (20:7–10). And when he does enter hell, Satan will not be in charge; he will be the lowest inmate there, the one undergoing the most horrible punishment ever inflicted on any created being.

Far from being in hell, Satan currently divides his time between roaming the earth “seeking someone to devour” (1 Pet. 5:8) and being in heaven, where he also engages in his doomed attempt to overthrow God’s Person, purposes, plans, and people. One way he seeks to do that is by constantly accusing believers before God’s throne (cf. 12:10). Satan ceaselessly harangues God about the unworthiness of believers, hypocritically appealing to God’s righteousness to further his own unrighteous aims. The unachievable goal of his accusations is to shatter the unbreakable bonds that inseparably link believers to the Lord Jesus Christ (Rom. 8:29–39). There is no possibility of that happening, however, since no one can snatch a believer out of the hands of Jesus or the Father (John 10:28–29). Still, Satan works on earth to turn God’s children against Him and in heaven to turn God against His children. But, as John proves, saving faith and eternal life are unbreakable realities.

The event that will cause the kingdom and authority of Christ to be established is the expulsion of Satan from heaven. So the saints offer praise that the accuser of our brethren has been thrown down, he who accuses them before our God day and night. As redeemed and glorified individuals, there was nothing Satan could legitimately accuse them of. Still, it must have grieved them that their suffering brethren on earth were subject to the devil’s slanderous accusations. Satan’s defeat will put an end to those relentless accusations (cf. Job 1:11; 2:5; Zech. 3:1; 1 Pet. 5:8).

The heavenly worshipers also offer praise because of events on earth, where their brethren overcame Satan. Ejected from heaven, Satan and his hellish hosts will vent their full fury on God’s people on earth (cf. 12:6, 13–17). There too, however, they will suffer defeat. Again speaking of a future event in the past tense because of its certainty, the inspired apostle John sees the victory already won and notes that the believers alive on earth overcame Satan, though it is yet to happen.