all’s for the best in the best of all pos- sible worlds

Everything that happens does so for a good reason, and things in general cannot be any better; generally used to present an optimistic worldview:
“The administrative departments were consuming miles of red tape in the cor- rectest forms of activity, and everything was for the best in the best of all possible worlds” (George Bernard Shaw, The Shew-
ing-up of Blanco Posnet, 1911). The proverb is a translation of a line from the French writer Voltaire’s philosophical tale Candide
(1759). In The Silver Stallion (1926), James Branch Cabell made the more cynical observation: “The optimist proclaims that we live in the best of all possible worlds; and the pessimist fears this is true.”