-tax exemptions (in some cases)
-excuse/reason to enslave "other" people for ones own benefit
-easier to brainwash the masses without needing to enslave
-can help the mind/soul be at peace
-people with similar beliefs will look out for you moreso than others
-optimism for what happens after death (if you truly believe and follow the rules)
-multiple wives (in some cases)
-spiritual journeys and connecting with god(s)
really once you eliminate the violence and trickery from those who control and spread religion, its got potential