The correct Einsteinian German appears to be: Der liebe Gott steckt im Detail (cf. http://www.benecke.com/einsteinprogramm.html)
(and there are German alternatives such as Gott lebt im Detail) and the satanic alternate is: Der Teufel liegt im Detail (very common, actually, but maybe just calqued from English) Who knows, maybe the concepts were borrowed from Latin to begin with, anyway. And as we can see from this thread God and the Devil do seem to be in the details! --Ken