The Spiritual Exercises is a book detailing the spiritual steps to understanding one’s Christian calling and also contains guides on how to discern where the Spirit of God is prompting us and to what end. Every Jesuit does a thirty-day retreat some time in the novitiate to discern how he is called and the necessary steps that need to be taken in line with Christ’s example of humbly accepting the Father’s will for Him. At the end of Jesuit formation and before Jesuits are approved for the final vows, which entail full incorporation into the Society, Jesuits go through a period of tertianship, which is similar to a third year in the novitiate. During this period of tertianship, the Jesuit will do the thirty-day retreat on the basis of the Spiritual Exercises in order to discern once more where the Spirit is prompting him to go and what to do for God and His Church.