Ebionites
The Ebionites were a fringe heretical Jewish Christian sect which existed between the late 2nd century and had all but died out by the 5th century.
According to Eusebius, the Ebionites believed that Jesus was not God and was not born of a virgin and that he earned the "rank" of Messiah through perfectly following the Law of Moses. Some also reputedly believed that they could also become Messiahs by following the law. They had very little in common with other Christians, and used their own gospel.
By the 6th century, the only place where Ebionites still existed was Arabia, where they would go on to influence the Islamic Prophet Muhammed.