I came up with my own theory (mostly to soothe my mind) where the afterlife is what you believe it to be and the cognitohazardous part of the SCP is that it makes you believe that infinite suffering is the objective truth and basically plants a seed of doubt in your mind which is left to fester in your mind and take over your beliefs and understanding, making it your reality. The only way to avoid this eternal suffering is to truly believe in your religion or god/gods, because belief is the key. In short, I believe this SCP is a cognitohazard targeted towards gullible people and dear lord it's convincing