Entrance Antiphon, Cf. Ps 119 (118):85, 46: The wicked have told me lies, but not so is your law; I spoke of your decrees before kings, and was not confounded, alleluia. St. Justin, apologist and martyr, was one of the most important Christian writers of the second century. He himself tells how his study of all the schools of philosophy led him to Christianity, and how he dedicated his life to the defense of the Christian faith as “the one certain and profitable philosophy.”