It is wajib upon us to believe in all the Prophets whose names are mentioned by Allah in His Book. We must also believe that Allah has sent Prophets and Messengers even we do not know the names and numbers of them but He knows only.
Allah Almighty says in the Quran:
''Some messengers We have already told you about, while some messengers We have not told you about.'' (Suran an-Nisa, 164)
''We sent messengers before you. Some of them We told you about, and some We did not tell you about.'' (Surah Ghafir, 78)
We must believe that the Prophets peace be upon them conveyed the guidance of Allah to the people and that they did not fail.