The non-religious viewpoint—that a moral sense evolves—
Raises up some thorny questions, while some others it resolves
The thing about selection that can give a fellow blindsight
Is that all success and failure is revealed to us in hindsight.
Predicting evolution is a right and awful mess,
Cos a change in the environment will influence success;
When selection pressures differ, they result in different features
In morphology, of course, and the behaviors seen in creatures
“Successful” might be bigger, might be smaller, might be smart
From a cuttlefish in hiding to a peacock’s walking art
From the flora in intestines to domesticated cow
Each of these has been successful; only hindsight tells us how.
A selectionist analysis applies to culture, too—
There’s variety apparent in the many things we do,
As we teach them to our children, replication of a sort
Differentially effective, when attempts may come up short.
When we ask the loaded questions, “What is moral? What is good?”
“Are there independent standards, what we shan’t and what we should?”
As the most successful culture, it should fill us with delight—
We will always look behind us, saying what we did was right
What we did was good and moral, and the gods looked down and smiled;
Now it’s thoroughly objective, and we teach to every child
All the Thou shall not’s we followed, every moral, every rule,
As the basis of our culture, in the church and in the school
In the battles over culture, had another party won
Then morality, objectively, is what that group has done.
The moral code of conduct that determines saints and sinners
Is the product of selection, in the history of the winners
Is there objective morality without God? No. The good news is, there is no objective morality with god, either. Come on, even if there were, how could we flawed humans recognize it without the possibility that we were being fooled? The same god that gets pointed to as the grand architect of good and evil, is the one who is on record as having fooled faithful believers in the past. If this god was the source of objective morality, we could never know it for certain.
An evolutionary view of morality, though, shows us that, for the most part, what is currently seen as moral in a given culture is what has led to the long-term success of that culture. Fortunately for us, that currently means usually being honest, not killing each other, doing unto others as we would have them do unto us, and the sort. We could do worse.
But just as a past selection pressure for, say, preferring fats and sugars has led to a current problem with weight, tooth decay, etc., when our current environment is vastly different from the one we evolved to fit, there is no guarantee that our current morality will be seen in the future as objectively good.
We are the lucky species who gets to view itself as the pinnacle of evolution (improperly, but understandably), ignoring the fact that there was no guarantee evolution would churn out something like us at all, and no guarantee we'll last as long as the dinosaurs did. The self-appointed arbiters of morality find themselves in the same position--on top, with no understanding that their position was never guaranteed or that their god may go the way of thousands of other obsolete gods.
For now, what is good is what has been good for the greatest number. To the extent that we can predict what will be looked back on as good, we know what we should do in order to be moral.
To the extent that we cannot know (and we cannot ultimately know, it being the future and all), we can take [very little] comfort in the knowledge that the gods don't know either. Oh, yeah, and in the long long long view, we all die, the planet vaporizes, and the universe suffers heat death, all in what would have been the first day of eternity.