7 And there was war in heaven. Michael and his angels fought against the dragon, and the dragon and his angels fought back. (Revelation 12:7)
And this, as a result of Isaiah's account of Lucifer's rebellion and fall from heaven:
12 How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations!
13 For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north:The name means "who is like God," the title given to one of the chief angels (Dan. 10:13, 21; 12:1). He had special charge of Israel as a nation. He disputed with Satan (Jude 1:9) about the body of Moses. He is also represented as warning against "that old serpent," called the Devil, and Satan, which deceiveth the whole world" (Rev. 12:7-9).
14 I will ascend above the heights of the clouds; I will be like the most High.
15 Yet thou shalt be brought down to hell, to the sides of the pit. (Isaiah 14:12-15 KJV)