Islam is not a new religion but the final culmination and fulfillment of the same basic truth that ALLAH (God) revealed through all His prophets to every people.
As there is only ONE GOD, there is only One Religion. Islam is the preserved pure religion of all prophets sent by ALLAH (GOD). Islam means the complete submission and obedience to Allah (God). Therefore, all prophets were indeed MUSLIMS because they were true submitters to the will of ALLAH, the Creator.
“Truly, the religion with Allah (God) is Islam. Those who were given the Scripture (Jews and Christians) did not differ except, out of mutual jealousy, after knowledge had come to them. And whoever disbelieves in the Ayat (proofs, evidences, verses, signs, revelations, etc.) of Allah, then surely, Allah is Swift in calling to account.” [The Noble Quran 3:19]
“And whoever seeks a religion other than Islam, it will never be accepted of him, and in the Hereafter he will be one of the losers.” [The Noble Quran 3:85]
(1) Prophet Abraham (peace be upon him) was MUSLIM
“Ibrahim (Abraham) was neither a Jew nor a Christian, but he was a true Muslim Hanifa (Islamic Monotheism – to worship none but Allah Alone) and he was not of Al-Mushrikun (the disbelievers in the Oneness of Allah, idolaters, polytheists, pagans, etc.)” [The Noble Quran 3:67]
“And this (submission to Allah, Islam) was enjoined by Ibrahim (Abraham) upon his sons and by Ya’qub (Jacob)(saying), “O my sons! Allah has chosen for you the (true) religion, then die not except in the Faith of Islâm (as Muslims – Islamic Monotheism).” [The Noble Quran 2:132]
(2) Prophet Joseph (peace be upon him) was MUSLIM
Joseph said: “My Lord! You have indeed bestowed on me of the sovereignty, and taught me something of the interpretation of dreams – the (Only) Creator of the heavens and the earth! You are my Wali (Protector, Helper, Supporter, Guardian, God, Lord) in this world and in the Hereafter. Cause me to die as a Muslim (the one submitting to Your Will), and join me with the righteous.” [The Noble Quran 12:101]
(3) Prophet Jacob and his sons were MUSLIMS
“Or were you witnesses when death approached Ya’qub (Jacob)? When he said unto his sons, “What will you worship after me?” They said, “We shall worship your Ilah (God – Allah), the Ilah (God) of your fathers, Ibrahim (Abraham), Isma’il (Ishmael), Ishaq (Isaac), One Ilah (God), and to Him we submit (in Islam, Muslims).” [The Noble Quran 2:133]
(4) Prophet Jesus (peace be upon him) and his disciples were MUSLIMS
“Then when ‘Isa (Jesus) came to know of their disbelief, he said: “Who will be my helpers in Allah’s Cause?” Al-Hawariun (the disciples) said: “We are the helpers of Allah; we believe in Allah, and bear witness that we are Muslims (i.e. we submit to Allah).” [The Noble Quran 3:52]
“And when I (Allah) revealed to Al-Hawarieen (the disciples)(of ‘Isa (Jesus)) to believe in Me and My Messenger, they said: “We believe. And bear witness that we are Muslims.” [The Noble Quran 5:111].
ALLAH (God) Almighty says in the Noble Quran:
“ Nay, We (Allah) fling (send down) the truth (this Quran) against the falsehood (disbelief), so it destroys it, and behold, it (falsehood) is vanished. And woe to you for that (lie) which you ascribe (to Allah by uttering that Allah has a son).” “ To Him belongs whosoever is in the heavens and on earth. And those who are near Him (i.e. the angels) are not too proud to worship Him, nor are they weary (of His worship).” [The Noble Quran 21:18-19]