Marcionism is an Early Christian dualist belief system that originates in the teachings of Marcion of Sinope at Rome around the year 144.Marcion believes Jesus Christ is the savior sent by God and Paul of Tarsus was his chief apostle, but he rejects the Hebrew Bible and the God of Israel (YHWH Elohim).

Marcionists believe that the wrathful Hebrew God is a separate and lower entity than the all-forgiving God of the New Testament.

This belief is in some ways similar to Gnostic Christian theology; notably, both are dualistic.Marcionism, similar to Gnosticism, depicts the Hebrew God of the Old Testament as a tyrant or demiurge.

Marcion is labeled as gnostic by Eusebius.

Marcion's canon consistsof eleven books: A gospel consisting of ten sections from the Gospel of Luke edited by Marcion; and ten of Paul's epistles.

All other epistles and gospels of the 27 book New Testament canon are rejected.

Paul's epistles enjoy a prominent position in the Marcionite canon, since Paul is credited with correctly transmitting the universality of Jesus' message.

R Marcionism is denounced by its opponents as heresy, and written against, notably by Tertullian, in a five-book treatise Adversus Marcionem, written about 208.

Marcion's writings are lost, though they were widely read and numerous manuscripts must have existed.

Even so, many scholars (including Henry Wace) claim it is possible to reconstruct and deduce a large part of ancient Marcionism through what later critics, especially Tertullian, said concerning Marcion.