In the juridical procedure in matters concerning the purity of faith, the sermon played an important role and was considered an effective tool in the fight against heresy. Preaching a public sermon was the first stage of undertaking inquisitorial activities. The trial also ended with a solemn sermon, called sermo generalis, immediately followed by the reading of the verdict and the abjuration of the accused or the surrender of the convict to secular authorities. They were preached in parish or cathedral churches, depending on the importance of the matter. Their authors were not always the inquisitors conducting the proceedings, but they were people who were well acquainted with the case. The sermo generalis began by emphasizing the authority of the Church, followed by a polemic against all the erroneous views of the accused. Only a few such sermons are known from the Gniezno metropolis, because they were not recorded in the Inquisitorial protocols.