Islam is not a new religion rather is one of the oldest religion in the middle east region whose founder was Ishmael the son of Abraham born by the Hagar the Egyptian maid of Sarah. Prophet Mohammed a descendant of Ishmael came to re-enforce it with a book known as the 'KORAN" known as the book of Ishmael as a New Testament from the Old Testament pre-Islamic religion.
The pre-Islamic religion was firmly established four hundred and thirty years later before the birth of Judaism through Moses for the fact that the children of Israel were in Egypt oppressed for four hindered and thirty years living in bondages as slaves. During the four hindered and thirty years, the pre-Islamic religion has spread across the Arab world by the Ishmaelite unlike the Israelites suffering in bondages without freedom of movement. Several prophets and saints were raised among the Ishmaelite which include, Prophet Job, Priest Jethro, Prophet Balaam and many others not mentioned. The book of Job and prophecies of Prophet Balaam written by Moses gives us an insight of the knowledge of the God of Abraham being worshipped by the Ishmaelite including prophet Job's friends and his household. Job is known in history as a man of faith who endured great temptation and God rewarded him twice of what he lost as his possession, who also prophesy of his resurrection on the day of judgment( Job 19:25). It is believed that the Ishmaelite also trading with Egypt who took Joseph to Egypt also took the religion to Egypt; evidently, the Priest of ON whose daughter Joseph married was an pre-Islamic Priest like Jehro the Priest of Median not of an Egyptian god else Joseph would have rejected her who gave birth to Menasha and Ephraim
The pre-Islamic religion was still in existence long before the birth of Prophet Mohammed whose worshippers were expecting the arrival of an Islamic Messiah who will come to refine and re-enforce the religion just as the way the Jews in Egypt were expecting the coming of a religious messiah who was to come and liberate them who later appeared as Moses.
The truth is that in every religious set-up, there must be remnant who will still hold on to the religion no matter the numbers of years and generation it takes. For example, in the days of the Apostles, Apostle Paul sill found some disciples whom he re-baptized to receive the Holy Spirit's baptism. According to an internet report, there are still good number of disciples of John available in Southern and Northern Iraq acknowledging John the Baptist as their Founder. In spite of the Christian churches around them, they still follow the life-stile of John the Baptist. Also in the Middle East, we also have some worshipers whose religion was believed to have founded by Prophet Elijah himself backed up with traditional history about the prophet's life.
Similarly, the pre-Islamic religion was still in existence with good number of followers before the birth of Prophet Mohammed who they later recognized as their promised Messiah according to the prophecy of Moses in Deuteronomy chapter 18 in relation to other accient prophecies about the coming of the Prophet Mohammed from the Ishmaelite sources which he came to fulfill through the introduction of the Holy Koran as a sign.
Prophet Mohammed came as Jesus Christ bringing the Old Testament Islamic religion together with the New Testament Islamic religion. Therefore, the Islamic New Testament include, the birth and Ministry of John the Baptist, the birth and the Ministry of Jesus Christ and the Virgin Mary being the key actors of the New Testament Islamic version.
However, each religion is identified by the founding religious prophets apart from Ishmael and Isaac with the introduction of the Holy books. The first include the Torah(the Old Testament scriptures) of Moses. The Second include, the New Testament of Jesus Christ which comprises the Torah and the New Testament called the "Holy Bible" both books comprise both historical records and prophecies; and Third is the Holy Koran of Prophet Mohammed which also comprise the accident pre-Islamic religion and the New Testament scriptures of the Holy Bible all in prophecies.
All the three books contain prophecies which are being revealed to the prophets as shadows of the past, present and future events. In as much as prophecy is concerned not all the words of those prophecies will fulfill exactly; sentence -by- sentence, word-for -word - paragraph - paragraph, verse- by- verse, chapter-chapter. But only part of them could be fulfilling either exactly or similarly, and also fulfilling in different shape from one generation to another. For more detail read my article on "NOTE ON PROPHECTIC and Historical ERRORS"