If god is omniscient, as a lot of religions state, (all knowing from second to second, from the beginning to the end of existance) then free will is only an illusion. You were predestined to believe or not believe from the beginning. So you are either rewarded or fucked from the start. If free will exists then god as defined can not exist and continued belief a delusion.
Being told you're delusional does not necessarily mean you're mental.