"Word" is a metonym for "message" or "teaching." AT: "those who will believe in me through their teaching" (See: [[rc://en/ta/man/translate/figs-metonymy]]).
Here the "the world" is a metonym that refers to the people who do not yet know God. AT: "the people who do not know God" (See: [[rc://en/ta/man/translate/figs-metonymy]])