The Rule is very Simple...
Do Good to others unconditionally without hoping for return. You will be blessed with what you would never thought of. thats a true virtue & Positive contribution to the society. we have no right to judge people from our typical perspective.
it reminds me an Algerian Man's Words - he came from no where to help us out and while moving he said ""Brother someday you will see people in a same situation - please stop & help them. your mother is alive? Please pay my Salaam to her and request her to pray for me by my name"".