Francis David’s selected sermons were published by the printing press of Alba Iulia (Gyulafehérvár) in 1569. These sermons are structured in an almost identical way: biblical text, brief summary, lessons and the proper sermon. most of the sermons, which adhered very strictly to the explanation of the text, were probably preached in the court of John Sigismund, prince of Transylvania, while others at services and workshops for priests who came to the religious disputes. As modern readers, we might posit the likelihood that bishop Francis David held training courses for pastors to prepare them for propagating the antitrinitarian doctrines whenever they had the opportunity. This paper examines to what extent Francis David’s sermons can be considered miniature encyclopaedias or repositories of useful knowledge as were the sermons of the 16th century. The study concludes that although these sermons were delivered in church, they were not addressed to the ordinary people of the congregation but were rather intended as a guide for Unitarian clergy.