In addition to the twelve main gods and the innumerable lesser deities, ancient Greeks worshiped a deity they called Agnostos Theos, that is: the Unknown god. In Athens, there was a temple specifically dedicated to that god and very often Athenians would swear "in the name of the Unknown god" (Νή τόν Άγνωστον Ne ton Agnoston).Apollodorus, Philostratus and Pausanias wrote about the Unknown god as well.The Unknown god was not so much a specific deity, but a placeholder, for whatever god or gods actually existed but whose name and nature were not revealed to the Athenians or the Hellenized world at large.
According to the book of Acts, contained in the Christian New Testament, when the Apostle Paul visited Athens, he saw an altar with an inscription dedicated to that god, and, when invited to speak to the Athenian elite at the Areopagus gave the following speech:
22"Then Paul stood in the midst of Mars' hill, and said, Ye men of Athens, I perceive that in all things ye are too superstitious[3].
23"For as I passed by, and beheld your devotions, I found an altar with this inscription, TO THE UNKNOWN GOD. Whom therefore ye ignorantly worship, him declare I unto you.
