Of the testimonies of poets and philosophers
How often, also, does Annæus Seneca, who was the keenest Stoic of the Romans, follow up with deserved praise the supreme Deity! For when he was discussing the subject of premature death, he said “You do not understand the authority and majesty of your Judge, the Ruler of the world, and the God of heaven and of all gods, on whom those deities which we separately worship and honour are dependent.” Also in his Exhortations: “This Being, when He was laying the first foundations of the most beautiful fabric, and was commencing this work, than which nature has known nothing greater or better, that all things might serve their own rulers, although He had spread Himself out through the whole body, yet He produced gods as ministers of His kingdom.”
And how many other things like to our own writers did he speak on the subject of God! But these things I put off for the present, because they are more suited to other parts of the subject. At present it is enough to demonstrate that men of the highest genius touched upon the truth, and almost grasped it, had not custom, infatuated by false opinions, carried them back; by which custom they both deemed that there were other gods, and believed that those things which God made for the use of man, as though they were endowed with perception, were to be held and worshipped as gods.
Source: The Divine Institutes (New Advent)