Morality serves as a guide for our actions - telling us how to do good vs evil; to do what is right vs wrong. We might propose several, not necessarily conflicting, moral systems depending upon the subject matter - good/right actions deemed as such based upon some end goal or other criteria. Here I'm focused on the concept of a society and the individuals that compose it. As per my previous post, I posit that our actions individually and collectively play a role in shaping our society at large. Hateful and selfish acts are detrimental to society - even posing the risk of destroying said society. On the other hand, if we act with the well being of others in mind, loving them as ourselves, then (all else equal) society will flourish. The individual and the collective whole will benefit and be made strong together.

Furthermore, It is objective because it is rooted in our human nature as intelligent social creatures. Mankind forms and lives in societies - and these societies require morality as spoken of above.