Instances where you 'trust and obey' something without regard to its epistemic truth but seeking something else out of that 'trust' or 'faith' should arguably be regarded as aliefs, not beliefs. So is it rational to alieve in a god? Well, the answer will probably depend on what your goals are and what god, or gods, you're alieving in at any given moment. If you're part of a group of warriors trying to enter some kind of collective berserker-like frenzy, it may be rational to alieve in a warlike deity like Mars, Thor or (at some level, at least) the Abrahamic god/Yahweh. But maybe you have other goals, and you'd do best by placing your faith in an entirely different deity.