Since Satan's fall (Isaiah 14:12-14; Ezekiel 2:11-18), Satan is actively battling with the angelic host, and with believers (Daniel 10:12-13; 1 Peter 5:8). Believers must be Aware and Alert to all of his schemes, giving him no opportunity to weaken our faith and testimony to the world (Ephesians 4:27). We are to resist him (James 4:7). The future battle finds Michael and the angels waging war with the dragon. This ultimate battle may be triggered by the rapture (1 Thessalonians 4:16-17). Michael and Satan, having known each other since they were created, Michael an archangel, defender of God's people; and Satan, the archenemy of God and His people.
Evicted from heaven, Satan's full fury will explode on humanity when he is cast to the earth for the last time. Once, the most glorious, created being (Isaiah 14:12), is forever known as Satan, or "the Adversary." He is the deceiver of the whole world, enemy of God, enemy of man.
In verses 10-12, there is another celebration, Satan and his demons have been defeated, and his presence has been removed from heaven. The Saints in heaven rejoice with an outpouring of praise, the accuser of the brethren has been cast down. They rejoice in the salvation, the power and the kingdom of our God... and in the authority of His Christ.
The joyous praise of triumph is followed by a sober warning to the earth (vs. 12). The Greek word for "wrath" refers to a violent outburst of rage. Satan's rage now becomes more violent because he knows his time is short.