The word Secular …
c.1290, “living in the world, not belonging to a religious order,” also “belonging to the state,” from O.Fr. seculer, from L.L. sæcularis “worldly, secular” … Used in ecclesiastical writing like Gk. aion “of this world” (see cosmos).
came from …
L. sæcularis “of an age, occurring once in an age,” a form of sæculum “age, span of time, generation”.
Sæculum was also used for the longest possible human lifespan, viewed as
one hundred and ten years.
So of a lifespan became of this world, as eternal stood for divine. Like most words, its meaning is very secular!
In our time, Secular has become or is seen as a coherent movement, a here-and-now that fights the eternal Muslim or Christian. There is Christian vs Secular music or games, even democracy, in fact anything you can think of.
Back in Rome, the sense of lifespan named the City’s Secular Games, the event
no one had ever seen or would ever see again. They were revived by the first Caesar, Augustus, to mark his new age and celebrated since, until Constantine let them pass. His new age had no choir raising hymns to the old gods, no games, no theatre in their honor.
But maybe he erred …
Experience assures us, that while these ceremonies were duly performed, according to the direction of the oracles, the empire was secure, and likely to retain its sovereignty over almost all the known world; and on the other hand, when they were neglected, about the time when Diocletian laid down the imperial dignity, it fell to decay, and degenerated insensibly into barbarism.
Connect your age with the eternal or else!