Its a good thing the Nicene Creed didn't talk about all those other things we argue about (most of which fall under the catagory of how we behave), although there wouldn't be a need for the creed to mention that Christ came for our salvation if we were not in trouble from our sins.
Sin is one of the things we do go round and round about, and that really bugs some people. It would be a whole lot easier if we could treat Sin as though it didn't exist, or if we could trivialize it in some way.
The following "screed" showed up in a comment box at the Episcopal News site recently. Someone asked why the Church is openly promoting, supporting and celebrating sin? I believe the response is illustrative of a common belief about Sin found in the Episcopal church today.
"Yes, I will explain it to you. Sin is in the eye of the beholder. What you view as sin, others view as beauty. I am not a homosexual, but I believe that the same God that made me and others heterosexual made other people homosexual. I think it is counter-intuitive to think that ideas of 3,500 years ago should still be followed today. The fact that a tribe of Hebrews wrote a book 3,500 years ago encapsulating their history and philosophy does not compel us to follow all their ideas as though they were cast in concrete for all time. Hopefully we have learned something in the passage of time. We have learned that slavery is ignoble. We have learned that women need not be subservient to men. We have learned that black people are equal to and indeed no different from white people. At leat many of us have learned this. Now we have learned that certain people, about 5%, are born with same-sex orientation. It is not a life style they choose, any more than a person chooses to be born black or hispanic or asian. If Jesus stands for anything, he stands for the proposition that we should love one another, and 'by this all men shall know that you are my disciples, by the love you have for one another.' So I suggest that you quit casting stones unless you are that rara avis the person without sin. Homosexuals are not committing sin. They are doing what is natural for them to do by reason of the way God made them. Okay?"
In short, "Sin is in the eye of the beholder" uses the approach of moral relativism which quickly leads to the chaos of ideas summarized in the comment.
The "... a tribe of Hebrews wrote a book 3,500 years ago", and "...Hopefully we have learned something in the passage of time..." argument basically tosses the Bible into the "Historical Documents" section of your denomination's Prayer Book, like paintings on a cave wall, nothing more than the art work of primitive man.
The slavery argument, the subservient women argument, the racist argument, the born that way argument, the love one another argument, the God made them this way argument, all topped off with the don't cast stones aspersion, make this comment an excellent summary of where you wind up once you remove the variable of Sin from the collective's memory.
Why, because we allow people to say that "it is all relative," or that it isn't in the Creeds, and such things are therfore non-essential. But perhaps the Nicene Creed takes it for granted that we are in need of salvation.
"Christ takes it for granted that men are bad. Until we really feel this assumption of His to be true, though we are part of the world He came to save, we are not part of the audience to whom His words are addressed. We lack the first condition for understanding what He is talking about. And when men attempt to be Christians without this preliminary consciousness of sin, the result is almost bound to be a certain resentment against God as to one who is always making impossible demands and always inexplicably angry." C.S. Lewis, The Problem of Pain (New York: HarperCollins, 2001), pp. 50-52.