Here's the translation from The Hellenistic Philosophers by Long and Sedley:
QuoteEpicurus, Letter to Menoeceus 123–4
(1) First, think of god as an imperishable and blessed creature, as the common idea of god is in outline, and attach to him nothing alien to imperishability or inappropriate to blessedness, but believe about him everything that can preserve his combination of blessedness and imperishability. (2) For there are gods – the knowledge of them is self-evident. (3) But they are not such as the many believe them to be. For by their beliefs as to their nature the many do not preserve them. The impious man is not he who denies the gods of the many, but he who attaches to gods the beliefs of the many about them. For they are not preconceptions but false suppositions, the assertions of the many about gods. It is through these that the greatest harms, the ones affecting bad men, stem from gods, and the greatest benefits too. (4) For having a total affinity for their own virtues, they are receptive to those who are like them, and consider alien all that is not of that kind.
This puts it in a more complete context, and now I see that Don has
QuoteThe gods do not exist in the way that the 'hoi polloi' believe them to, because they do not perceive what maintains the gods.
I've never noticed this phrase before and it adds quite a bit to chew on!