The War Against God
The war against God began when Lucifer tried to make himself equal to God. And God threw him out of heaven, along with a third of the angels who joined his rebellion.
Satan told Adam and Eve if they ate the forbidden fruit, they would be like God. They believed him instead of God. That severed their relationship with God and got them kicked out of the Garden of Eden.
When Jesus died for us, he restored our relationship with God. He set us free from sin and death and Hell, and he utterly defeated Satan forever.
In this passage of Scripture, God was addressing Lucifer:
“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!
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:
I will ascend above the heights of the clouds; I will be like the most High.
Yet thou shalt be brought down to hell, to the sides of the pit.” Isaiah 14:12-15