He does think that the letter to the Corinthians, known now as 1 Clement, was of great worth but does not seem to believe that Clement of Rome was the one author ("Book 3", Chapter 3, Verse 3) and seems to have the same lower status as Polycarp's Epistle ("Book 3", Chapter 3, Verse 3). He does refer to a passage in the Shepherd of Hermas as scripture ("Mandate 1 or First Commandment"), but this has some consistency problems on his part. Hermas taught that Jesus was not himself a divine being, but a virtuous man who was subsequently filled with the Holy Spirit and adopted as the Son (a doctrine called adoptionism). But Irenaeus's own work, including his citing of the Gospel of John ("Jn". 1:1), indicates that he himself believed that Jesus was always God. In the late 4th century Epiphanius of Salamis (died 402) "Panarion" 29 says the Nazarenes had rejected the Pauline epistles and Irenaeus "Against Heresies" 26.2 says the Ebionites rejected him. In the 2nd and 3rd centuries Eusebius's "Ecclesiastical History" 6.38 says the Elchasai "made use of texts from every part of the Old Testament and the Gospels; it rejects the Apostle (Paul) entirely"; 4.29.5 says Tatian the Assyrian rejected Paul's Letters and Acts of the Apostles; 6.25 says Origen accepted 22 canonical books of the Hebrews plus Maccabees plus the four Gospels, one epistle of Peter "perhaps also a second, but this is doubtful," the apocalypse of John, by John an "epistle of very few lines; perhaps also a second and third", and the epistles of Paul who "did not so much as write to all the churches that he taught; and even to those to which he wrote he sent but a few lines." In all, Origen's canon is suggested to be identical to that of Athanasius. Between 140 and 220, both internal and external forces caused Proto-orthodox Christianity to begin to systematize both its doctrines and its view of revelation. Much of the systemization came about as a defense against the diverse Early Christian viewpoints that competed with emerging Proto-Orthodoxy. The early years of this period witnessed the rise of several strong movements of faith later deemed heretical by the church in Rome: Marcionism, Gnosticism and Montanism.