There are two practical epistemologies of survival. One is of physical survival. We seek to believe that which will prolong our physical lives as much as possible. Another is of emotional or hedonic survival. We seek to believe that which gives us emotional relief, so that we aren't "underwater". Negative feelings can feel so bad that we feel like we are going to die, even if literally speaking we are not. Because the drive for relief of pain and fear of death, and for not dying, are so deeply rooted in us viscerally, these practical epistemologies are powerful and persuasive a lot of the time.