Simple mathmatics tells us that anything falling into the category of "metaphysical" is not worth believing in. As "god's" nature is not known by any human, nor could it ever be, as it is beyond our physical comprehension by the very nature of its design, no one can tell you what god actually is, or what an afterlife would be composed of if it does in fact exist.
The probability of any religion or spiritual idea being correct is 1/ infinity, which is
approximately equivalent to 0.
Even if a massive hand were to reach forth from the heavens and speak of salvation through a given path, what is to tell us that this is not some deception by "god's" twin brother, Tim, who is the prince of beastiality and seashells?
The excuse that "god is beyond out comprehension" is a two way road, as it means we, not even in our supposed afterlives will know what the flying fuck is going on. On the other hand, if god is within our comprehension, then eventually it could be proven or disproven.
Religion is good for making small children behave and serving as a comfort to those unable to cope with the harsh and cold idea of oblivion.
I myself am not mentally capable of believing because I think too much. Not one theory, statement, or observation regarding religion has ever given me a reason to beleive in anything besides the physical world I percieve around me.
I made a comic about this thats actually my favorite one I've made, but stripcreator's down.