Chuckle. I'm not surprised considering the state of today's ethics.
Indeed, the entire reason for acting ethical boiled down to "it makes good business sense." If people trust you they will do business with you; if they don't trust you they'll go to your competitor. Trust becomes the very foundation of all human transactions.
This is merely situational ethics. Do we do good only to gain someone's trust? Many German companies trusted Hitler and they trusted him, so by your standards, they were all ethical people. That isn't ethics - it's pure self interest.
We are social critters. We need each other to survive, because individually we are weak and make a great meal for a goodly number of predators.
Sounds like another just so story to me. What does that have to do with right and wrong? When you make a moral decision, do you first wonder if natural selection would agree with your choice?
Because we need to work as teams, trust is paramount. The great ethical philosophies, including those predating Christianity, realized this. The golden rule cropped up independently in a half dozen civilizations simply because it is rational and promotes survival. One did not need to be a God-fearing Christian to realize this.
So, if the golden rule cropped up independently, how does that in any way negate the truth of Jesus' words, and how does show that moral Christian principles are wrong? It merely shows that some people got it right.
I have stated this over and over and over again on these threads. Moral principles are either the invention of man (on the cultural, govt. or personal level), and therefore relative with no moral force or authority, or they are from God which makes them universal to all men. Those are the only two choices. Which do you choose?
It doesn't, and if you think that is what this is about, the entire conversation has gone right by you. Christian moral principles are simply rationally-derived and because they are rational they have survived this long (people have a tendency to chuck that which makes no sense). However, these same "Christian" principles were derived independently by other cultures, in many cases long before Christ came into this world.
There is nothing inherently evil about a rationally-derived morality. If the morality promotes survival, the morality will survive. If it does not, it will not. The Golden Rule promotes survival.