After the arrival of Ammon we find in Mosiah 21:32-33 that king Limhi and many of his people had "entered into a covenant with God" and "were desirous to be baptized; but there was none in the land that had authority from God." Furthermore, "Ammon declined doing this thing, considering himself an unworthy servant." One might ask, What was going on?
According to Monte Nyman, Ammon's reasons for feeling unworthy are not specified. Perhaps Mosiah chose Ammon and his companions after Mosiah had been teased to the point of weariness. (Mosiah 7:1) Though they felt themselves unworthy to baptize, they were indeed capable of leading the people back to Zarahemla. The Lord uses people according to their abilities. Another possibility is that Ammon was worthy but the Lord inspired him to decline lest the captive Nephites lose their incentive to return following their baptism. [Monte S. Nyman, "Bondage and Deliverance," in Studies in Scripture: Book of Mormon, Part 1, p. 266]