Satan, of course, cannot get God to make a mistake.
“God cannot be tempted with evil, and he himself tempts no one” (James 1:13).
It has always been fully in God’s power to destroy Satan at any time. Indeed, the complete defeat of Satan has been foretold in passages like Revelation 20:10. But God has allowed Satan to continue to rebel for a while. Why does God allow this struggle? The reasons are not all clearly revealed. However, God has revealed that the struggle is very serious.
An example of this can be found in Revelation 12, which describes “war in heaven.” God’s angels, led by the angel Michael, fought against Satan and his angels. God’s angels were much stronger. They threw their enemies out of heaven. Then the struggle continued on the earth.
And the great dragon was thrown down, that ancient serpent, who is called the devil and Satan, the deceiver of the whole world— he was thrown down to the earth, and his angels were thrown down with him… But woe [great trouble] to you, O earth and sea, for the devil has come down to you in great wrath, because he knows that his time is short! (Revelation 12:9,12).
“Woe” means “trouble.” This is a warning to us that the earth has become the battleground.