Notice Jesus doesn't promise the trouble will end. He says “in this world you will have trouble,” stated flatly, as an ongoing fact, not a temporary phase to be endured until circumstances improve. And yet in the very same breath he offers peace and tells them to “take heart.” The peace isn't contingent on the trouble disappearing. It's grounded in something else entirely: “I have overcome the world.” The victory is already accomplished, even while the trouble is still ongoing and unresolved. That's a different kind of peace than we usually chase, not the peace of a solved problem, but the peace of a settled outcome underneath an unsolved one.