For comfort and solace.

It helps to believe there's a divine purpose in pain and suffering - that at the end of it all there's a just reward for those who've lived a proper life and borne their disappointments well, and a fitting punishment for those who haven't. It's a relief to believe that we're not alone when it feels like we're all alone.

It helps to lessen the fear of dying. It takes the edge off the nagging remnants of doubt that at the end of life all our trials and tribulations may have been for naught, and nothing but a return to an empty void is the only thing that awaits us.