There is this recurring image, or motif, of the God and the Devil sitting down on friendly terms to bargain for souls.
Think "Spanish Train" by Chris de Burgh. Another, more popular version, is that of God and the Devil playing Chess, the stakes are the same.
Now this is a curious idea, as it somehow diminishes both the influence and omnipotence of God. Nowhere in the Christian tradition is this allowed. Other, more pagan traditions or religions offer a more balanced view of Good and Evil.
"That power I serve that wills forever evil and does forever good", by Mikhail Bulgakov, seems more in line with Christianity, the Devil is a necessary foil for God, indulged by him even, tolerated, one can imagine God sitting down to play Chess with him and gently tolerating his cheating in the understanding that he was maintaining the illusion of equals, whereas in fact by very definition he's superior.
...just some curious ideas wrapped up in that motif...