In these pages Bernardo Olivera helps us to discern and recognize how the devil can act in our life and what kind of influence he can have. What is the relationship between Satan and the spiritual combat implied in our own journey to union with God? This book brings together the advice of the principal spiritual masters who have treated the subject with the realism that comes from their own experience of the devil's worst temptations, such as the laziness, bitterness and indifference that comes from the vice of acedia. The call is not to fight Satan directly, but to persevere in the humility and patience of Christ.