[Morgeruat]

Weeeeeeeeeelllllllll..... if you don't mind hearing the mormon perspective, Jesus offered his(God's) plan for bringing about the salvation of men, that they come to earth and choose to serve him, or not, and those that served faithfully retun to glory (more to it than this, but this will suffice for now), and Lucifer presented his plan as well, that all the souls would come to earth and basically be forced to be good, and all would return to glory, and he wouuld get the credit, when God sided with Jesus's plan Lucifer couldn't accept it, and those who followed him were cast out. there is quite a bit more to it, but without getting into a huge religious debate I'll let this stand