 The attempt to refute Biandrata’s treatise only convinced him of the veracity of Biandrata’s arguments, especially when the famed Hebrew scholar Immanuel Tremellius could offer him no support of the doctrine of the Trinity from the Old Testament.Sylvan became part of an Antitrinitarian cell that included Adam Neuser, Matthias Vehe-Glirius, Jakob Suter and Johann Hasler.In 1570 John Sylvan wrote an Antitrinitarian manifesto entitled "True Christian Confession of the Ancient Faith of the One True God and of Messiah Jesus of the True Christ, against the Three-Person Idol and the Two-Natured False Deity of the Antichrist".