Good & evil are mental, not environmental. Marcus Aurelius 5.26

Marcus' take on good and evil: these are properly labels we bestow in the mind, upon our own unique reaction to events and things whose manifestation in the world at large is generally neutral (neither good nor evil per se). What makes a thing good is our ability and will to make good use of it, not some inherent quality it possesses that we should aspire to manipulate or control from a position outside our minds. The Stoic way to handle bad things: consider how their badness is derived from some personal mental judgment, or attitude, that then becomes subject to alteration. I can conquer the bad in my life best by seeing how it might be reclaimed for the good.

Τὸ ἡγεμονικὸν καὶ κυριεῦον τῆς ψυχῆς σου μέρος ἄτρεπτον ἔστω ὑπὸ τῆς ἐν τῇ σαρκὶ λείας ἢ τραχείας κινήσεως καὶ μὴ συγκρινάσθω, ἀλλὰ περιγραφέτω αὑτὸ καὶ περιοριζέτω τὰς πείσεις ἐκείνας ἐν τοῖς μορίοις. ὅταν δὲ ἀναδιδῶνται κατὰ τὴν ἑτέραν συμπάθειαν εἰς τὴν διάνοιαν ὡς ἐν σώματι ἡνωμένῳ, τότε πρὸς μὲν τὴν αἴσθησιν φυσικὴν οὖσαν οὐ πειρατέον ἀντιβαίνειν, τὴν δὲ ὑπόληψιν τὴν ὡς περὶ ἀγαθοῦ ἢ κακοῦ μὴ προστιθέτω τὸ ἡγεμονικὸν ἐξ ἑαυτοῦ.

Let the ruling principle of your soul, the part that governs, remain unshaken, unmoved by the motion of your flesh, whether that motion be slight or stark. Your mind should not meld with your body: instead, let it mark a space apart for itself, where it can view the attitudes and affections of your body from a proper distance, sighting them on a wide horizon that includes every part of you and of your action. Whenever any attitude or emotion presents itself to your body coherently, so that mind and flesh respond together as one, don't attempt in that moment to oppose the material impression thrust upon your senses. But do not allow your mind to judge anything outside itself as definitively good or evil.