The importance of the Apostle Paul for the development of Christianity is difficult to overestimate: he is called the “architect of Christianity.” Paul's letters occupy almost a third of the total volume of the New Testament; he is glorified by the Church as the “apostle of the Gentiles.” Why was the Apostle Paul destined to play such a significant role in the development of Christianity? Why did Christ Himself call him? These and many other questions are answered by the proposed book, in which the biography of the Apostle Paul, as it emerges from the book of the Acts of the Apostles and from his own letters, is presented in a broad historical context. The publishing layout is preserved in PDF A4 format.