Back to Athens
"People of Athens, I see that you are in every respect religiously exact. For as I walked about and looked carefully at your objects of worship, I even came upon an altar inscribed, 'To a God Unknown.' Now what you thus worship unknowingly I would proclaim to you" (Acts 17:23).
To date, no such altar inscription has been found, either in Athens or any place else (though a mutilated 2nd-century inscription found at Pergamum, in modern Turkey, is sometimes interpreted to include the words "unknown gods"). A number of ancient literary sources do attest to the existence of altars to "unknown gods," but these invariably speak of "gods" not "god." The Church father, Jerome (340-420) thought that the inscription read, "To the Gods of Asia and Europe and Africa, to unknown and strange gods" and that Paul changed the wording to suit his sermonic intention. Thus, though archeological evidence is lacking, literary evidence is conclusive that there were, indeed, altars at Athens to unknown gods;probably not to an unknown god.Paul (or Luke), like preachers from his time to ours, took an existing reality and put it to the service of his preaching.
The most picturesque explanation for the existence of these altars of unknown gods is that given by Diogenes Laertius (200-250) who recounted that, in order to relieve Athens of a plague, Epimenides (ca. 600 BCE), a Cretan wonder-worker, "took sheep, some black and others white, and brought them to the Areopagus; and there he let them go whither they pleased, instructing those that followed them to mark the spot where each sheep lay down and to offer a sacrifice to the local divinity. And thus, it is said, the plague was stayed. Hence even to this day altars may be found in different parts of Attica with no name inscribed upon them, which are memorials of this atonement."