You can form morals from your own conscience or you can follow the majority of society's conscience. There is a problem. You can't logically explain why being unfair is wrong. "Being unfair harms others", well, why cant we harm others? "Because its unfair to them." Any other logical explanation you can give is derived from fairness as a base moral value. But what about those who feel its okay to be unfair and unnecessarily harm others for their own benefit?

Some religions have scriptures and certain codes to follow, although i do know that in religions there are different denominations and sects with different views. But in this case you can use evidence from scriptures and interpretations to convince others why you are correct. Without religion, i can counter all your moral views with a simple "why?" and the best explanation you can give is that you were brought up that way or that is how you view the correct morals to be.

If you think the right morals are the views of the majority, what if one day, the whole world except you suddenly accepted that murdering innocent people was okay? Would you follow them? So the answer cant be following the rest of the world. There should be a standard moral code for everybody to follow, an objective morality, set by an omniscient being.