Letters 75.17

Then neither desire nor fear shall rout us. Undisturbed by fears, unspoiled by pleasures, we shall be afraid neither of death nor of the gods; we shall know that death is no evil and that the gods are not powers of evil. That which harms has no greater power than that which receives harm, and things which are utterly good have no power at all to harm.

Seneca, Letters to Lucilius 75.17, translated by Richard Mott Gummere