Morality, good and bad....they are fluid social constructs. Not a single moral concept has been timeless and consistent from one side of the world to the other.
There is one constant, timeless and consistent from one side of the world to the other, it is flexibility of a moral. A natural instinct of a human done suiting the occasion is moral.
This means that we are to return good for good, and to exercise benevolence when it is called for, and to do good with natural eagerness as between kindred, when that should be appropriate.