Baptist successionism (or Baptist perpetuity) is one of several theories on the origin and continuation of Baptist churches. The theory postulates an unbroken lineage of churches (since the days of John the Baptist, who baptized Christ) which have held beliefs similar to those of current Baptists. Groups often included in this lineage include the Montanists, Paulicians, Cathari, Waldenses, Albigenses, Lollards, and Anabaptists. However most scholars agree that the Baptists originated within 17th-century puritanism.
The theory proposes that Baptists have an unbroken lineage from the early church, while claiming that over time bishops or pastors started to assume more authority which led to the Catholic church being born and which led to errors.
Groups often included in the succession line are Montanists, Novationists, Donatists, Paulicians, Cathars, Waldenses, Petrobrusians, Arnoldists, Henricians, Hussites (partly), Lollards, and Anabaptists.
Supporters of the theory argue that groups such as Bogomils, Paulicians, or Cathars were Baptist in doctrine instead of Gnostic; with, for example, Berlin Hisel arguing that many charges put towards Bogomils were false.
Hisel claimed that the Novatians were credobaptists and accepted rebaptism.
Though Augustine mentions that the Novatians rebaptized converts, the evidence for them being credobaptist has been called "weak".
Berlin Hisel argued against the accusations put towards the Paulicians, such as rejection of the writings of Peter the Apostle and the Old Testament, and argued that the Paulicians held to the orthodox view of the Trinity, a reason for the denial of many charges towards Paulicians was that the sources we have were made by their opponents. It was also put forward that the Paulicians believed in Believer's baptism along with the Bogomils.
Hisel claimed that the charges of rejecting baptism likely meant a rejection of infant baptism and trine-immersion, which could have been taken as rejection of baptism itself, since the sources that exist about Bogomilism are from people who opposed them, and thus he argued that these sources should be taken with suspicion.