There is of course a certain amount of tension which somehow soured their relationship. There is actually no 'somehow' about it, the problem all began over a dispute whether to educate monkeys or not.
For our purposes I have given God and the Devil the image most familiar to said monkeys, another bone of contention for Devil as he feels he's had unfair press treatment, fake news and all that. I considered giving him a POTUS face but the poor Devil has suffered enough. Just to give an insight into the 'mysterious ways' of these 'supreme beings' - they're actually monkeys just like us but have evolved a little more - they're not better, not even wiser sometimes, they're just..... older..
So as you can see, God and the Devil started arguing semantics whilst the monkeys they modified down on Earth were hell-bent on self-destruction. My views change every time I look at the situation. I was taught God was the G(o)od guy and the Devil was just pure (D)evil. I began to sympathise a little with the Devil because as far as I could make out, his only crime was trying to give us monkeys an education.
It sort of made me wonder about this God bloke, I mean making Adam and Eve homeless just because of a little fornication and fruit consumption seemed unduly harsh in my opinion. He told them to metaphorically 'Fuck off' with the old 'Go forth and multiply' speech. Due to his reluctance for us to have knowledge I'm sure he didn't mean 'Go forth and do maths'........ or did he?
Anyway, I changed my opinion again. Perhaps God wasn't being mean. Adam and Eve weren't victims of the bailiffs at all, it was just the meltdown causing sea-levels to rise. On top of that, maybe God had the foresight to know giving monkeys technology would just hasten our urge to destroy each other, and the planet with us.