Original sentence: He is best known for his early controversial thesis regarding the role and dating of the Marcion in the history of the New Testament canon and reconstructions of the writings of the pagan opponents of Christianity, Celsus (1987), Porphyry (1994) and Julian the Apostate (2004)
Edited sentence: He is best known for his early controversial thesis regarding the role and dating of the heretic Marcion in the history of the New Testament canon and reconstructions of the writings of the pagan opponents of Christianity, Celsus (1987), Porphyry (1994) and Julian the Apostate (2004)