God is a creature living in the Intruder's cocoon resembling Heaven, and is based on the God of Christianity. He appears to be a face made up of clouds.
God, or "The Lord" appears twice in the series. In The Von Neumann-machine he is summoned by Gabriel to judge Storm and his friends as they are 'animals who dared to infiltrate the Kingdom of Heavens disguised as New People'. As "New People" don't need to eat and do not multiply themselves, Storm's talk about food and Ember's body gave Gabriel the conclusion they are animals. God tells Gabriel to throw them into Gehenna's Depths (Hell).
God appears once more in The Genesis-equation when Marduk is wreaking havoc in Heaven. God is threatening Marduk with his wrath when he sees that Gabriel has been 'damaged'. Marduk is however not at all impressed and orders his guards to open fire upon God. God dissolves into rain, making Marduk the new master of Heaven.