Many people believe that the only source of morality is God’s authority. According to them, we are morally required to do certain things and not to do others simply because God thus commands us. There would be no other reason why we should act morally. As a consequence, if you do not believe in God, these people argue, you cannot have any moral values or commitments and everything will be permitted.
There is, however, a problem with this idea – a problem that was first articulated by Socrates in Plato's dialogue "Euthyphro" and has since come to be called the “Euthyphro problem”: Does something become right because God says so, or does God say that something is right or command that we do it because it is right? Does God’s command make something right, or is God merely the best judge of what is right and wrong (so that being right explains his command)? Which of the two options is preferable?
If the latter, then an atheist should in principle be able to discover the difference between right and wrong even without commitment to divine authority. He or she would then also not require anticipation of divine punishment, for example, in order to have a reason to act morally. This means that we would not even need to believe in God in order to be moral and to be committed to moral values.
In order to find a tentative answer to our question, we need to look closer into the difference between the two options. According to the first, there is no other reason for why we should act morally than the fact that God commands us thus. This means that there is nothing in our actions or attitudes themselves that would explain what makes them moral or immoral. Thus if God had commanded us to lie, kill our neighbors, disrespect our parents, steal and to go after our friends’ spouses, then these would be thereby moral actions. It seems that in this picture, God has created moral values by a sheer arbitrary act of the will.
According to the second option, however, God had a reason to command us to do certain things and not to do others, and his reason lies in the very nature of the kinds of actions addressed in those commandments. Thus God did not create moral values by an arbitrary act of His will; rather, they are an intrinsic part of the world -- or, alternatively, a part of God other than His mere will. In this picture of God and morality, God would not have commanded us to murder and steal precisely because he would have seen that such actions are evil in themselves, by their very own nature.
Even a Christian has good reasons to believe that the second option presented in the Euthyphro problem is more convincing. This is because in Christianity God is believed to be most benevolent and omniscient. He is, in other words, the perfection of moral goodness and wisdom.
Considering these traditional divine traits, God would not have made arbitrary choices, and certainly not choices that are not based on considerations of what is best for his creatures and best in its own nature. Thus, he must have had a reason to give us his commandments, and the best reason would have been for him the fact that they were representative of the nature of goodness itself.