Many gathered themselves to him, drawn by the fame of his holy life. Them he took for his comrades, and laboured earnestly among them to cleanse the Church in those parts from the pollution of heresy and simony, and spread abroad the Apostolic Faith. He and his had to fight with almost countless hardships. Certain enemies broke by night into the monastery of San Salvi, to destroy John and his monks, set the church on fire, pulled down the huts, and mortally wounded all the monks; but the man of God perfectly healed them all by the sign of the Cross. One of his monks named Peter also passed unhurt through a vast and raging fire. At length John and his disciples got the peace which they longed for. He purged Tuscany of the pollution of simony, and restored the faith throughout all Italy to its first purity.
He entirely built several monasteries, and furnished them and others with buildings. He restored in them the strict observance of the Rule, and gave them holy laws. He sold the furniture of the Church to feed the poor, and found the very elements subject to him to bend stubborn hearts withal. He used the Cross like a sword to drive out devils. In his old age, worn out by abstinence, watching, fasts, prayers, and punishing of the flesh, his strength utterly gave way, and he often repeated the words of David: My soul thirsteth for God, for the mighty God, for the living God―when shall I come and appear before God? When he was at the point of death, he gathered his disciples together and exhorted them to love one another, and, after a little while, ordered the following words to be written down, which he wished should be buried with him: I, John, do believe and confess that Faith which the Holy Apostles preached, and which the Holy Fathers have ratified in the four Councils. At length, at Passignano, where he is held in the highest reverence, after a vision of angels which lasted three days, he passed away to be with the Lord, upon the 12th day of July, in the 78th year of his own age, and in that of salvation 1073. He is illustrious for countless miracles, and Celestine III enrolled his name among those of the Saints.