I've discussed before my own code of ethics: Love is good; hate is bad. Alleviating suffering is good; inflicting it is bad. I came up with these guidelines based on observations of what made me happy and what didn't. This hearkens back to Kriss's comment about the Golden Rule, and while he may have been off on the timeline, the point remains that people knew right from wrong long before religions started cropping up.
I agree with XR4-IT when he said that the concept of being saved by grace alone nulls personal responsibility. No matter how you want to spin it, that is the logical conclusion of the get-out-of-jail-free, believe-accept-saved dogma. Patrik says (and gets Paul to back him up) that Jesus' sacrifice is not a ticket to sin, but why not? Why does a Christian continue to strive to be moral, despite a belief that Jesus will pay the price for his sins anyway? Why do non-Christians strive to be moral, despite not believing in eternal consequences for our wrong actions?
I think Ray hit the nail on the head when he said that empathy is the driving force behind our ethics (and I'm not saying that just because I sleep with him). A moral code is present in all of us whether we're Christian or not, which is why I think Christ and Christianity have nothing to do with it. As I've pointed out, this code varies a great deal depending on our culture and beliefs, and is not measured against any external absolute code. godwillbegod brought up sociopaths and psychopaths. These are people that we recognize as not functioning under the same innate ethical code as the rest of us. What's more likely: that these people are possessed by demons or that something in their genetic code is off?
Now, some thoughts on adultery. I don't think anyone condones it, although I don't think that extra-marital relationships are always wrong, as there are some people who are happy in polyamorous relationships. But in cases where both partners have agreed to monogamy, they should keep that agreement.
I'm fortunate in that I can only imagine the devastation of an unfaithful spouse. Adultery--defined as a polyamorous relationship to which not everyone involved has consented--would fall under the "Inflicting suffering is bad" clause of my personal moral code. But the idea that death was ever a just consequence for it is abhorrent. Patrik says that in a very real way, adultery destroys lives, and I agree. Perhaps you remember, Patrik, at one time I felt that rapists deserved the death penalty, because rape, too, destroys lives. However, that destruction is temporary. Victims of murder do not get any second chances. Death is so final that I have very strong reservations about capital punishment, even for murder.
I'm sure the debate about the origin of our sense of morality will continue for quite some time, in religious and scientific circles alike. However, I think we can safely say that wherever else morality may have come from, it most certainly did not come from the Bible.