The Riddle of Epicurus, or Problem of evil, is a famous argument against the existence of an all-powerful and providential God or gods. As recorded by Lactantius:
God either wants to eliminate bad things and cannot, or can but does not want to, or neither wishes to nor can, or both wants to and can. If he wants to and cannot, then he is weak - and this does not apply to god. If he can but does not want to, then he is spiteful - which is equally foreign to god’s nature. If he neither wants to nor can, he is both weak and spiteful, and so not a god. If he wants to and can, which is the only thing fitting for a god, where then do bad things come from? Or why does he not eliminate them?
Epicurus’ view was that there were gods, but that they were neither willing nor able to prevent evil. This was not because they were malevolent, but because they lived in a perfect state of ataraxia, a state everyone should strive to emulate; it is not the gods who are upset by evils, but people.
Parallels may be drawn to Buddhism, which similarly emphasizes a lack of divine interference and aspects of its atomism. Buddhism also resembles Epicureanism in its temperateness, including the belief that great excesses leads to great dissatisfaction.
From ‘Epicureanism’ on Wikipedia.