How do moral norms serve these functions? In following moral norms we engage in behavior that enables these functions of morality to be fulfilled. When we obey norms like “don’t kill” and “don’t steal” we help ensure the security and stability of society. It really doesn’t take a genius to figure out why, but that hasn’t stopped some geniuses from drawing our attention to the importance of moral norms. As the seventeenth century English philosopher Thomas Hobbes and many others have pointed out, if we always had to fear being injured or having our property stolen, we could never have any rest. Our lives would be “solitary, poor, nasty, brutish, and short.” Besides providing security and stability by prohibiting certain actions, moral norms also promote collaboration by encouraging certain actions and by providing the necessary framework for the critical actions of the “promise” – that is, a commitment that allows others to rely on me. Consider a simple example, one that could reflect circumstances in the Neolithic Era as much as today. I need a tool you have to complete a project, so I ask yo to lend it to me. You hesitate to lend me the tool, but you also believe you are obliged to help me if such help doesn’t significantly harm you. Moreover, I promise to return the tool. You lend me the tool; I keep my promise to return the tool. This exchange fosters trust between us. Both of us will be more inclined to cooperate with each other in the future. Our cooperation will likely improve our respective living conditions.
Multiply this example millions and millions of times and you get a sense of the numerous transactions among people that allow a peaceful, stable, prospering society to emerge. You also can imagine how conditions would deteriorate if moral norms were not followed. Going back to my tool example, let us imagine you do not respond positively to my request for assistance. This causes resentment and also frustrates my ability to carry out a beneficial project. I am also less likely to assist you if you need help. Or say you do lend me a tool, but I keep it instead of returning it as promised. This causes distrust, and you are less likely to assist me (and others) in the future. Multiplied many times such failures to follow moral norms can result in mistrust, reduced cooperation, and even violence. If I do not return that tool peacefully, you may resort to brute force to reacquire it.
–Ron Lindsay, pgs 78-79, The Necessity of Secularism