Isaiah 14:12 - 14
KJV - 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:
For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
YHWH knows all. He wouldn't be God if he didn't.
The events of Revelation 12:9 havent happened yet. That event is the trigger of the great tribulation.