Shaykh al-Islam Ibn Taymiyah said: The correct view is that the Messenger is one who is sent to a disbelieving people, and the Prophet is one who is sent to a believing people with the sharee’ah of the Messenger who came before him, to teach them and judge between them.
The scholars say that a Prophet is one who receives Revelation from Allaah of a law, but he is not commanded to propagate it, only to practice it himself, without being called upon to disseminate it. A Messenger is one who receives Revelation from Allaah of a law and he is called upon to propagate it and to act upon it. Every Messenger is a Prophet, but not every Prophet is a Messenger.
Allah knows best.