32 Profession of the Christian faith is not intelligible without strong, lively apostolic fervor; in fact, "everyone is bound to proclaim his faith to others, either to give good example and encouragement to the rest of the faithful, or to check the attacks of unbelievers," (57) especially in our time, when the universal Church and human society are beset by many difficulties.
Source: Princeps Pastorum (Vatican.va)