Think of the internal and external qualities of intelligence, strength, beauty, leadership, artistry, etc. and add morality to the list. The way I see it, morality is a human quality just like other human qualities, and just as all these qualities can be inherited through our genes (provided by God) and learned/improved (through our own effort) so can morality be inherited and learned. Some of us might have an inherent sense of morality that guides our behavior and are left wondering how sociopaths can behave the way they do, without caring about anyone else? At the same time, we might recognize that certain life events have taught us to be more sensitive to the views, wants, and needs of others, in particular our family, before it's too late to matter.
But I think this question misses something important: merely knowing between right and wrong isn't really anything special on its own. Before I came to Islam, one of the questions that often passed my mind was that if Islam is merely about teaching us the difference between right and wrong, then what is so great about that (my younger self would ask)? Since I thought that if I, even at this young age, understand that we should only do onto others as we would want for ourselves, then what could be so great about a book that is merely reiterating that point?
I have come to see that the beauty of the Qur'an (something that 'religious' and atheistic texts do not possess), lies not in its prescription of morally upright behavior, but its changing of the hearts and minds of a people so that they can actually do as they understand/preach. One might wonder to what extent atheistic professors of morality and ethics are actually capable of softening the hearts of their students to lead morally upright lives. And I wonder, for example, how effective business ethics classes have been in MBA programs leading up to this latest financial crisis.
A good moral understanding is simply us walking along the stream of human intellect. The Qur'an is what can take us to the juncture where the two streams meet:
18:60 And so, in the course of his quest for knowledge, Moses said to his young friend, “I shall not give up until I reach the junction of the two streams, though I march on for ages in my quest.”
[The Divine revelation shows the way and the outcome with conviction. When Moses was a young man, not yet commissioned as a Prophet, he was constantly in search of truth 93:7. God chose His Prophets and assigned them their mission at the appropriate time. The young Moses knew that the human intellect was the source of conceptual knowledge whereas the Divine revelation is the extrinsic knowledge from beyond human faculties. Intellect and revelation: The Two Streams of knowledge]
18:61 But when Moses with his young friend reached the junction of the two streams, they forgot all about the fish. And it disappeared into the sea. [Moses became more concerned about his people in bondage. Interestingly, fish is an ancient symbol of worldly life with all its glitter]
18:62 And after the two had walked some distance, Moses said to his young friend, “Bring us our lunch, the journey has been tiring.”
18:63 Said his friend, “Would you believe it? When we rested at the rock, I forgot about the fish and none but Satan, my wandering thoughts, made me forget it. And it took its way into the sea. How strange!
18:64 Moses said, “That is what we were seeking!” And the two turned back retracing their footsteps. (Moses retired to rest in deep thought.)
18:65 (Moses wondered how exciting the merging of the two streams would be! And he imagined that) he found a servant of Ours, upon whom We had bestowed grace from Our Presence and to whom We had imparted knowledge from Ourselves.
[A close examination of verses 60-65 is quite revealing. From this point on the young friend suddenly disappears. Also consider the way the fish disappeared, and how then, Moses remarks, "That is what we were seeking". I agree with Allama Muhammad Asad that the 'fish' here is only figurative. I also understand that the young friend of Moses is none else but his own youthful enthusiasm taking him to a great quest. Then in 18:64 Moses goes back retracing his footsteps. So, what happens next is most probably his deep contemplation at rest. The mystical story is worth pondering. The enlightened man who meets Moses at this juncture, and later his weird actions, definitely grant him an allegorical and not a tangible presence. For these reasons I think that in 18:60-82, the Qur‟an is relating the intellectual search of Moses rather than his physical experience]
I'm not sure I agree with some of the explanatory comments or perhaps I'm misunderstanding them. If fish is to mean worldly life with its glitter, then why would Moses have said "That is what we were seeking!" after it (the fish) disappeared into the sea? For me it makes more sense that it is telling us that we cannot approach the meeting of the two streams with impatience. In other words, when Moses' friend lost the fish, he did so because he became impatient with what lay at the meating of the two streams so much so that he forgot his practical responsibilities, which at that point happened to be to remember their lunch. This is reiterated right after as well:
18:66 Moses (deep in his contemplation) said to the man, “May I follow you that you may teach me some of the knowledge and guidance which you have been taught?”
18:67 He said, "Surely, you would not be able to have patience with me.
And it goes on to show that Moses was to learn about patience through this servant of God. I can't comment on whether or not this actually happened or it was Moses in deep contemplation, but it does seem that both events are more a note on the importance of patience in approaching divine revelation.