II. He asks him to restore the ancient Catholic doctrine.
Wherefore, most peace-loving prince, vouchsafe for the Faith's sake to avert this danger from your Godly conscience, and let not man's presumption use violence upon Christ's Gospel. In my sincere desire, which is shared by the bishops that are with me, that you, most Christian and revered prince, should before all things please God, to whom the prayers of the whole Church are poured with one accord for your empire, I give you counsel, for fear lest, if we keep silence on so great a matter, we incur punishment before the tribunal of Christ.
I entreat you therefore before the undivided Trinity of the one Godhead, which is injured by these evil doings, and which is the guardian of your kingdom, and before Christ's holy angels that all things remain intact as they were before the judgment, and that they await the weightier decision of the Synod at which the whole number of the bishops in the whole world is gathered together: and do not allow yourselves to bear the weight of others' misdoing. We are constrained to say this plainly by the fear of a constraining necessity. But keep before your eyes the blessed Peter's glory, and the crowns which all the Apostles have in common with him, and the joys of the martyrs who had no other incentive to suffering but the confession of the true Godhead and the perfect continuance in Christ.
Source: Letters (New Advent)