General question about the possibility of objective moral truth

[Faith No More]

I think, every human being who thinks about morality has to admit, that his feelings of what is right or wrong, are – if he is honest to himself – claiming to be more than just a subjective feeling. If a fighter of the IS is knocking at my door with the intention to cut off my head then I will hardly think: “OK, in my opinion it’s wrong what he wants to do, but in his own opinion it is right – so, at the end we are both equal and none of us is more right with his point of view than the other.” –Honestly, I will insist, that I AM the one who see the things OBJECTIVELY right in that moment and not the IS fighter. But I can only be right with that if morality actually can be true in itself.
If morality has NO truth in itself, then our own feelings about Right and Wrong are cheating us.

To understand morality you have to understand how we, as humans beings, develop it. Neuroscience shows that the brain is born with the capacity for morality, but it has to learn just what exactly is moral through social cues. Our neurons develop in a manner that is affected by what we experience and perceive, and the part of the brain that determines morality develops based upon what it picks up as moral from its surrounding environment. That's why it "feels" like killing is inherently wrong, because your brain has developed in an environment that found it extremely morally unacceptable. You've developed over time your sense of right and wrong through your neural structures, so that's why something can feel so profoundly wrong.

Now, of course you're going to run into universal themes that pop up throughout different cultures, because much of our ethical values are a result of problems that humankind has run into throughout the centuries, such as resource management and the concept of ownership. Each culture is going to face similar problems, so similar ethical values are going to be found in different cultures. If you study various cultures throughout history you'll find that ethics vary greatly.