All people, after meeting the Messiah, must believe in and serve him all through their lives, most of all John the Baptist, who came with the mission of the Messiah's forerunner. Therefore, John the Baptist should have served Jesus with all his strength as one of his disciples.
Even John's father was told of the mission of his son upon his birth: "And you child, will be called the prophet of the Most High, for you will go before the Lord to prepare his ways, to give knowledge of salvation to his people. . . (Luke 1:76-77). However, we cannot find any instance in the Bible where John the Baptist actually served Jesus.