In the last years of the life of Yochanan HaTzadik (Saint John) lived in Ephesus (in modern Turkey). The long lived holy man was often carried to meetings of the kehillah (group, ekklesia, church) of Yeshua's disciples. He used to repeat to them all the time, "My little children, love each other." When the disciples asked him why he was always repeating the same thing, he replied, "it is the commandment of Adonenu (our Lord), and if you keep it, it alone suffices."
(told by Jerome, quoted in the Navarre commentary to St John, p. 20).