The Original Sin
Once upon a time in an epoch before this creation, Lucifer sinned against God almighty.
Ezekiel says,
“Thou hast been in Eden the garden of God; every precious stone was thy covering, the sardius, topaz, and the diamond, the beryl, the onyx, and the jasper, the sapphire, the emerald, and the carbuncle, and gold: the workmanship of thy tabrets and of thy pipes was prepared in thee in the day that thou wast created. Thou art the anointed cherub that covereth; and I have set thee so: thou wast upon the holy mountain of God; thou hast walked up and down in the midst of the stones of fire. Thou wast perfect in thy ways from the day that thou wast created, till iniquity was found in thee.”
Ezekiel 28:13-15
Not only that, but Lucifer led a portion of the angels into her rebellion and there was war in heaven. Fortunately, Michael stood with Gabriel and defeated Lucifer casting her and Her followers out of the sides of the north far from the presence of God.
A desperate wager
God, about to cast Lucifer into the lake of fire, heard her speak this challenge:
“You are unrighteous for even those you are about to create cannot serve you without sinning just as I have. Before you condemn me to an eternal punishment prove that man can succeed where I have failed. If you prove they can walk perfectly before you, then I will accept my punishment, but if they fail, I will in nowise suffer torment. Put now therefore two trees in the midst of your garden and give them free will to choose. As they choose so will be both our fates.”
God said,
“So be it, lo I have put two trees in the midst of my paradise: the tree of life and the tree of the knowledge of good and evil. As man so chooses thus shall be both your fates.”