Ebionitism (coming from a word meaning “the poor” in Hebrew) refers to a Jewish Christian heretical sect of the early church. They regard Jesus as the Messiah and insist that it is still necessary to follow all Jewish laws, traditions and rites (a Legalism heresy). They rejected the writings of Paul as “apostate”. As suggested by their name, they put a high premium on voluntary poverty. Some scholars differentiate Ebionites from groups such as the Nazarenes or Messianic Jews, other considered them the same. Ebionites believe in a Monophysitism-style angelology, claiming that Christ is a great archangel who was incarnated in Jesus and then adopted as the Son of God (quasi-Adoptionism and Psilanthropism).
Psilanthropism is sometimes used to describe Ebionitism, and is considered part of the Adoptionism family of heresies. It teaches that Jesus is “merely human” and is the literal son of two human parents (coming from the Greek for “plain human” or “mere human”). Modern iterations of this heresy include the Unitarian Church (Unitarianism) and the Unification Church.