Next week's heresy will be "part two": Marcionism. They are closely related enough I wanted to do them in a series, but distinct enough to not put them in the same post.
Cerdonianism is a Gnosticism sect founded by Cerdo in the 2nd century. Cerdo was the teacher of Marcion, who founded Marcionism. Very little is known about this sect, other than they held fairly typical Gnosticism beliefs—two “causes”, one perfectly good and one perfectly evil. The evil “cause” created the world and was the Old Testament Jewish God. Christ is the Son of the good “cause”, and He was sent here to oppose evil, but they deny his humanity (Monophysitism). As the body and all material things are evil, they were strict Asceticism followers and had a very severe moral system which must be closely followed for “salvation” (Legalism and Pelagianism).