You're looking at it all wrong.

Think of it as a double blind study.

God knew Lucifer was a disease, but no one else could see it.

God make the earth, and it was good. God made Man, male and female, and he was good. God allowed Lucifer to tempt man, and now the study is on it's way. God comes here to teach us, and Lucifer has Him killed.

Now all the Angels can see from this little test that Lucifer would have been the ruin of all if he hadn't been contained.

In return for our part in this show all study we are offered a wonderful life that will last forever.

The only catch is, that we have to choose sides and show it.