The empire is filled with a mixture of gods, as long as you dont pray or involve yourself with any of the outlawed religions its all cool (sort of) with them.
Its not just what god you support either, mutants, non sanctioned wizards, some sanctioned wizards and even if you look at them funny - they will burn you.
Also they have almost complete authority on who to burn - the more important you are, the more evidence you need. End of the day they are only human and majority of them are just as corrupt (polically) as anyone else.
Don't, after rolling that final 1 too many, flip out, climb up on the table and jump up and down on your opponent's models screaming 'APOCALYPTIC BARRAGE, MOTHERFUCKER!!!'.