"Don't Fear God
Don't Worry about Death
What is Good is Easy to Get;
And What is Terrible is Easy to Endure"
-Epicurus 341-270 BC
Essentially he's saying that Gods, if they exist, are unconcerned with human life and thus we should not be concerned with them. As I said before, a god that is absolutely apathetic toward humanity might as well be a god that doesn't exist. In layman's terms, just forget about the whole God-thing, okay?
Next is "Don't worry about Death." My more rational followers will interpret this exactly how Epicurus meant it. Basically he's saying that since there is no consciousness after death, you shouldn't really be concerned with what happens after you die. In his own words,
"Death means nothing to us...when we exist, death is not yet present, and when death is
present, then we do not exist."
Wise words for someone who lived over 2 millenniums ago. The rest is glaringly obvious
and has been reinterpreted numerous times into thousands of cheap motivational posters in some form or another. But the tetrepharmakos as a whole is definitely one knockout of a creed, in my humble opinion.