John Frith (1503–1533) was burned at the stake in Smithfield on 4 July 1533, and was one of the earliest evangelical martyrs during the reign of Henry VIII. Many scholars consider his death one of the greatest losses in the early period of theological reforms in Tudor England. The paper first surveys the life of the young reformer who was a disciple and assistant of the Bible-translator William Tyndale (ca. 1494–1536). He also authored several books, the most famous ones are on the false idea of purgatory and the Lord’s Supper. The present study focuses on the latter theme, especially on his debate with Sir Thomas More (1477–1535). Frith’s short anonymous statement on the subject entitled Christian Sentence was read by the famous humanist Lord Chancellor, who responded him in a long letter A Letter of syr Tho. More knyght impugnynge the erronyouse wrytyng of John Fryth against the blessed sacrament of the aultare. This letter gave occasion for Frith, already a prisoner in the Tower of London, to refute More and to present his views at greater length in A Book Made by John Frith Prisoner in the Tower of London Answering Unto M. More’s Letter. The present study analyzes these three documents which also illuminate why this young man chose martyrdom. Shortly before his execution Frith wrote a short statement: The Articles for Which John Frith Died. This document as well as his Christian Sentence and The letter from Prison are also published in the present volume for the first time in Hungarian.