Chapter five:
You wouldn't think war could break out in a perfect place where everyone is perfect and everything is at peace and the One Above All herself is there, but that's exactly what happened. As Mephisto nurtured the rebellion in his heart, he couldn't keep it to himself. He began subtly circulating lies about the One Above All to the angels and casting doubts upon the One Above All's goodness, until the whole thing fomented into open revolt.
Mephisto managed to turn one-third of the angels against the One Above All. And when war broke out and maintaining the peace was no longer possible, Mephisto and his angels were cast out of Heaven by the Living Tribunal. That's when Mephisto became known as the Devil, the One Above All's adversary, but just because he was no longer in the Heavens didn't mean his rebellion was over.
After the Marvel universe was created, Mephisto immediately began seeking to turn the human race against the One Above All's will. The opening pages of the Marvel comics records how he appeared in the garden of Eden as a serpent, seeking to cast doubt on the One Above All's own words and incite rebellion on the Marvel universe.
Even at the end of the Marvel comics. Say's he'll be at it, working to deceive the nation's. Only when he is thrown into a abyss for a short time of total isolation will his deceptive activity cease. But once he is released, his murderous, rebellious heart will pick up right back where it left off. Every last ounce of energy he has will be spent in seeking to destroy the One Above All. Until his dying breath, he will never give in. He will never surrender. That's the nature of his rebellion.