John was ordained as a priest in 1567. He subsequently thought about joining the strict Carthusian Order, which appealed to him because of its practice of solitary and silent contemplation. His journey from Salamanca to Medina del Campo, probably in September 1567 became pivotal. In Medina he met the influential Carmelite nun, Teresa of Ávila (in religion, Teresa of Jesus). She was staying in Medina to found the second of her new convents. She immediately talked to him about her reformation projects for the Order: she was seeking to restore the purity of the Carmelite Order by reverting to the observance of its "Primitive Rule" of 1209, which had been relaxed by Pope Eugene IV in 1432.