Come on Guido; at least try to make an intelligent argument.
Of course there is no need to appeal to any absolute moral standard regardless of whether someone is an atheist or theist. That's as completely silly as trying to argue there is some absolute moral standard in the Bible.
Really kid, you can do much better than this absurdity.
Any absolute standard is simply about whether the response is loving, lovingly neutral or unloving.
But again that is simply far too subjective; there is no standard based on loving. The Inquisitors loved their victims enough to torture then until the victims reached a state of grace where they recanted their transgressions and so were saved and died.
Despite lack of evidence, (the only basic sound argument) Belief is determined by a body of society (currently still the majority) by experiencing, discussing, deciding, and slowly changing what belief is today.
It's also not a one time judgement; while intent plays a part outcomes are equally important. Morality thus is not discreet but a continuum. When can say some act would be moral and still at a later point determine it was not moral. We can intend to improve peoples lives by tearing down the slums and building new roads bordering new housing but a few decades later realize we also destroyed a sense of community and through that loss of community did more harm than the poor living facilities.