This week's heresy reveals an interesting piece of early church history, with the first big "split".
Novatianism (also known as Sabbatianism) was a 3rd century heretical sect that is connected with Albigensism and Donatism. They wanted to reject giving communion to baptized Christians who denied their faith or performed the formalities of pagan sacrifice under Roman pressure of persecution, calling them “Lapsi” or “lapsed Christians”. They also held that second marriages were unlawful. The leader, Novatian, was the first antipope after he challenged the election of Pope Cornelius in 251. They called themselves the “katharoi” or “Puritans”. They went so far as to rebaptize (like Anabaptism) their converts to separate themselves from the “corrupt Catholic Church”. They were condemned as heretical by a synod in the 4th century.