A classic piece of literature that discusses the identity, spiritual mission, and theological foundations of diocesan priests in the Catholic Church. This book debunks the notion that a diocesan priest's spirituality is merely a copy of the spirituality of monasteries or religious orders. The author asserts that diocesan priests have a unique and theological place within the Church. They are called and ordained to serve the local church (diocese) under the guidance of the Bishop. This calling reflects the ministry of Jesus Christ who lives, works, and is rooted in the midst of the world. The spirituality of diocesan priests is not a closed, ascetic spirituality, but rather a missionary and pastoral spirituality. This book describes how a priest must sanctify himself through the duties of daily ministry (shepherding the people, serving the parish, and administering the sacraments). This work highlights how priests' encounters with various levels of society in their territorial territory (diocese) become a means of their spiritual growth. The book also explores the spiritual meaning of priestly promises, such as obedience to the Bishop and celibacy. This obedience is seen not as merely administrative compliance, but as a bond of communion (fellowship) in building the body of Christ. This bond provides stability and depth to the relationship between priests and their parishioners. Overall, the contents of this book present a profound yet practical theology. It offers a foundation for priests to maintain a clear separation between their personal spiritual life (prayer) and their daily apostolic duties.