When he was seventeen he decided he wanted to become a monk or friar. The Franciscans would not take him because, they said, he was too stupid. The Capuchins threw him out after eight months because he broke everything. Eventually, a Franciscan house at La Grotella accepted him as a stableboy. He prayed and fasted and did his best to perform every task to perfection. Eventually the delighted brothers decided to accept him as one of their equals, and in 1628, he was ordained priest.
From that time onwards Joseph of Cupertino was continually passing into ecstatic trances, sometimes even appearing to float above the ground. No meals could be taken in the monastery without some extraordinary interruption because of Joseph's miraculous behaviour. He was noted for his great austerities, his angelic purity, his great devotion to Our Lady and especially for his ardent love of God.