What promises do religions make that are unanswerable (or weak answerable)by other approaches or systems?

What promises do religions make that are unanswerable (or weak answerable)by other approaches or systems? What benefit does religion offer to the ruler or ruling class? In what ways does it limit the ruler or ruling classes? In what ways does it attract attention of those outside of power (yes, the marginalized, but also those stuck in the middle)? Further, is it able to meet its promises? In what ways? In your answer refer to atleast three civilizations and religions. Ensure that the text on Sunjata is part of the discussion.