What is your evidence that morality was originally codified in religions?
We have morality handed down to the present from the earliest religious texts we have available. However early philosophical texts from people as far separated as Aristotle and Confucius present ethics as a subject that is independent of religion. I don't think there is a clear case in the historical record for saying that ethical systems come from religion, or that they don't.
It is, of course, clear that religion has been used as a way to codify ethical systems and propagate them through the ages. This doesn't mean, though, that they come from religion. After all local political power has historically come from force of arms, but likewise political realities have tended to become intertwined with religion.
But the basis of many of the basic foundations that you can point to behind Addison's sense of morality (and mine) may go back a lot farther. (Insert standard lecture on sociobiology and the potential evolutionary roots of our basic ethical imperatives.)
Cheers,
Ben