In an article well worth reading about the religious practices of the Ebionites found here, author Stephen Tomkins notes, "... it sounds not unlike Islam in all those respects."
There is a reason for that. The Ebionites followed a text known as the Gospel of Matthew to the Hebrews. Although most scholars would say it was lost to history, it is possible that its precepts can be found today in the early suras of a text far more famous known as the Quran.
If true, this could be a fascinating study. Two of the major controversies in the early Christian church were the nature of the divinity of Jesus (how could he be both a man and God?), and the extent to which Christians were to follow Jewish practices and traditions. Although the Apostle Paul's conviction that Jesus was both fully God and fully man and that being Christian meant leaving everything Jewish behind eventually won the day, many groups disagreed. As they and their gospels were declared heretical by early Church councils, they were forced away from the Christian geographical centers of power and some of them ended up in Arabia and Yemen. Two of these were the Nestorians and the Ebionites. Although they are sometimes lumped together, they are distinct in that the Nestorians believed in the divinity of Jesus whereas the Ebionites saw him merely as a Prophet.
One difference between those declared heretics and the orthodox church was that the former often followed only one text, or gospel, rather than all the books that became the New Testament. The Ebionites followed The Gospel of Matthew to the Hebrews (called by some scholars simply the Gospel of the Ebionites). It is probably a second-century compilation including passages from Matthew, Mark, and Luke that emphasizes the compassion and humanity of Jesus while denying his divinity. The Ebionites believed that Jesus was a man, not God, and that a presence called the Holy Spirit descended upon him at his baptism and remained with him until just before his crucifixion. They followed the dietary and health practices of the Jews and placed much emphasis on rituals such as ablution, fasting, and circumcision.
Available online studies of the Ebionites found here and here seem unaware of their continued history after persecution possibly forced them from the Levant into Arabia in the early centuries of the Christian era. There are several reasons for this historical lack of knowledge. One is the fact that the Ebionites were less significant and less known than the Nestorians, the larger Christian sect in Arabia at the time that did accept the divinity of Jesus. Another is that Christian historians typically had little access to ancient Islamic history, until recently only available in Arabic, that made scattered references to the Nusraniyah (taken from the town of Nazareth, this is the Quranic word used to describe the non-orthodox Christians in Mecca at the time of Muhammad).
There is another and more significant reason. After Muhammad, Muslims paid little or no attention to the beliefs of Christians and Jews in the Arabian Peninsula other than to compare them critically to Islam. Muslims believe the Quran was revealed directly to Muhammad from Allah via the angel Gabriel. They historically had little interest in the beliefs of others, and even less interest in the possibility that their religious texts and practices influenced Muhammad and the formation of the Quran.
Muslims have placed much emphasis in creating an imaginary genealogy for Muhammad that passes through Abraham all the way back to Adam. Of more historical relevance is that Muslim scholars emphasize his lineage from his ancestor Qusay to Muhammad's grandfather Abdel Mutallib, but ignore that same lineage from Qusay to grandson Assad who was the grandfather of Khadijah, Muhammad's first wife, and Waraqa bin Naufal, the Prophet's distant uncle. The reason Muslims have deliberately ignored that side of the family is that it included relatives including Waraqa and possibly Khadijah herself who were members of the Nusraniyah.
Ancient historian Abu Faraj Al Isfahani noted in his Kitab Al Aghani that Waraqa bin Naufal converted to Nusraniyah, and biographer Ibn Ishaq describes him as a Hanif, one who believed in only one God.
Hadith compilers Bukhari and Sahih Muslim both state that Waraqa bin Naufal translated the Book of the Hebrews and the Gospel into Arabic. It is possible the book they meant was the Gospel of Matthew to the Hebrews.
Among the characteristics of the Ebionites was compassion for the poor and the orphaned. Waraqa bin Naufal, who was both a scholar and the leader of the Ebionites in Mecca, took a special interest in his young relative the orphaned Muhammad. He saw in him qualities of leadership, spent much time with him, and over the years taught Muhammad the Gospel of the Ebionites as well as the contents of the Torah. Waraqa bin Naufal performed Muhammad's marriage to Khadijah, and groomed Muhammad to replace him as the Ebionite spiritual leader in Mecca.
(When presented with criticism of Muhammad's later multiple marriages, Muslims often point out that the Prophet remained in a monogamous relationship with Khadija for 25 years. The reality is that Muhammad's marriage with Khadijah was essentially a Christian marriage, with both divorce and having more than one wife not allowed to the Ebionites).
When Muhammad first announced that he was receiving revelations from God, the revelations were in large part the stories he had learned from Waraqa bin Naufal. Waraqa encouraged Muhammad to consider himself a Prophet, with the understanding that just as Abraham had been the Prophet to call the Jews back to Allah, and Jesus the Prophet who called his generation back to Allah, so Muhammad would be the Prophet who could call the Arabs back to Allah. It is interesting to note that at this time Muhammad did not see himself as founding a new religion, but only in calling people back to the Islam of Abraham, Moses, and Jesus.
The influence of Waraqi bin Naufal upon Muhammad and his revelations continued until Waraqa died. It is not accidental that the Hadith writers note that "revelations ceased for some time" following the death of Waraqa. The reason, of course, is that Muhammad was no longer learning from his Ebionite uncle.
The presence of the Gospel of the Ebionites in the short, poetic Meccan suras with their vivid descriptions of hell and Muhammad's repeated claim that he is a Prophet just like Abraham, Moses, and Jesus is something most Muslims are not allowed to even think about, at least publicly. It's much easier, and safer, to just toe the party line. I would encourage Muslims to be a little more open in their thinking and scholarship.
(Acknowledgements to Joseph Azzi, author of The Priest and the Prophet, for much of the above material).