Author: Alonso de Oropesa. Born in Oropesa and studied arts and theology in Salamanca. The date he entered the Monastery of Hieronymites in Guadalupe is unknown. During the years 1451-1452 he was nominated Prior of the Convent of St. Catherine in Talavera de la Reina and Superior General of the Order of St. Jerome in October 29th, 1457. He remained Superior General and was also appointed Prior of the Convent of St. Bartholomew in Lupiana (Guadalajara) until his death. Fray Alonso was greatly appreciated as a preacher in and out of the Order. King Henry IV valued his advice and collaboration. Alonso Carillo, Archbishop of Toledo, commissioned him in 1460 to conduct an inquisition among the conversos in Toledo that were in fact guilty of apostasy. Fray Alonso died on October 28, in the Convent of Lupiana.

• 1r-203v Fray Alonso de Oropesa: Lumen ad revelationem gentium et gloriam plebis Dei Israel, de unitate fidei et de concordi et pacifica aequalitate fidelium
  The author aims to protect New Christians from the attacks of Old Christians and to emphasize the equality of these two categories within the Catholic Church. Fray José Sigüenza in his History of the Order of St. Jerome (ca. 1605) provides a summary of Oropesa's work that was begun in 1450, during the disputes over conversos in Toledo, 1449. When Alonso de Oropesa was appointed Prior of Talavera in 1451, he had written apart from the prologue of this work, 40 chapters. After ten years of interruption, he resumed work in 1462 by order of Archbishop Carillo of Toledo, and in 1465 concluded chapter 52, the last of the first half of the work completed on Christmas Eve 1465. The second part, intended to present practical conclusions, was never written. Alonso de Oropesa's work was terminated in 1465, including a broad introduction dedicated to Archbishop Alonso Carrillo. The title Lumen ad revelationem gentium et gloriam plebis Dei Israel is from Luke 2, 32 meaning to reveal the love, grace, and mercy of God, and the way of love and salvation to all Christians. Therefore, racial segregation of the New Christians can destroy charity, religion and the Gospel. More than an apology, it is a theological treatise on the unity of all those who believe in Jesus Christ and enjoy the benefit of light by him. Oropesa defends the Pauline interpretation of the Gospels, which claims that the inclusion in the Christian community erases all previous differences among their members.