For centuries this book has been a sure reference for Christian spirituality, so much so that it can be considered the most read book after the Gospel. Meditated on in monasteries and in religious and priestly life, used as a manual for Christian formation by many generations of Christian laypeople in the world, the Imitation of Christ, whose author, unknown, although placed in a monastic environment between the thirteenth and fourteenth centuries, is a simple and concrete treatise on ascetic life. The tension with Christ who animates it makes it a fundamental text for tracing a way of undressing and abandoning the old man to dress up and embrace the new man , Christ the God who knocks at the door of our person and asks to be allowed to dwell in us.