John González was born in 1430 of a well-to-do family in Sahagún de Campos, Spain. He studied under the Benedictines in his native city, showing great promise. In 1454 he was ordained priest by the bishop of Burgos and held the office of chaplain at the church of Saint Gadea. When his bishop died in 1456, John resigned as chaplain and moved to Salamanca to pursue further studies in canon law and theology, obtaining degrees in both. He was named preacher of the city of Salamanca and a member of the University College of Saint Bartholomew. As preacher, he drew large crowds due to his clarity, eloquence and sincerity, while also incurring opposition and criticism for his denunciation of the sins of both nobles and commoners. On June 18, 1463, John renounced all his offices in order to join the Augustinian Order in Salamanca. He was professed the following year on August 28, and thereafter continued his preaching ministry while exercising various responsibilities in the Order as prior and delegate to various provincial chapters. Because of his renown in the city he became a principle agent of reconciliation between rival groups, thus bring peace to Salamanca. He was also respected as a defender of the rights of workers and the common folk. Characteristic of his personal life was his great devotion to the Eucharist, his humility and simplicity. John died on June 11, 1479 at the age of 49, was beatified in 1601 and canonized in 1691 by Innocent XII. It was thought by some of his contemporaries that he had actually been poisoned in retaliation for his condemnation of the immoral lifestyle of a public figure. His remains are venerated in the cathedral of Salamanca where he is honored as patron of both the city and the diocese.
Saint John's life bears witness to the necessity of being attentive always to the call of God and generous in responding, regardless of where the summons might lead. There can be no limits placed on one's availability when a person experiences within the force of God's love - whether in one's state of life or in the carrying out of one's responsibilities even at a high price.