Here "word" refers to the message about Jesus. This can be stated in active form. Alternate translation: "Those who believed spread the word of the Lord through the whole region" or "Those who believed went everywhere in the region and told others about the message of Jesus" (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-activepassive]])