25 Have confidence, therefore; be brave and steadfast soldiers. We wish to counsel you in the words of St. Ignatius, martyr, although We know you do not require such counsel: "Serve Him for whom you fight. . . May none of you desert Him! Your baptism must be a shield; your faith a helmet; your charity a lance; your patience a suit of armor. Your works should be your credentials, so that you may be worthy to receive your reward."
Source: Meminisse Iuvat (Vatican.va)