Muslim is an Arabic word that means one who submits to Allah (God in English and same God worshiped by Jews and Christians) and worship Allah as the one and only one God with no partner, no son, no companion, no associate, and no equivalence. The Arabic root of the word is ‘Salem’ that means being in peace. So, Muslim lives in peace within him/her self and also within the society he/she lives in.

Accordingly, all people were created on the principle of Islam, that is submission to God. All God prophets were calling people to Islam. Islam per God revelation of Torah to Moses is called Judaism. Islam per God revelation of the Bible to Jesus is called Christianity. Islam per God revelation of the Quran to Muhammad is called the very name Islam

So prophets Noah, Abraham, Moses, Jesus, and Muhammad (Peace be upon them) are all Muslims per Muslim definition above.