VATICAN CITY (CNS) -- Christians facing difficulties and discrimination, especially in the Middle East, can learn a valuable lesson from Japanese Christians who survived by clandestinely baptizing, praying and hiding during 250 years of harsh persecution, Pope Francis said. "Difficulties and persecution, when they are lived with trust, confidence and hope, purify the faith and strengthen it," he said in his general audience talk in St. Peter's Square Jan. 15. "Be true witnesses of Christ and his Gospel, authentic children of the church, always ready to give reasons for your hope with love and respect," he told pilgrims from the Middle East. The pope continued a series of talks on the sacrament of baptism, underlining that it is through baptism that "we become members of the body of Christ and the people of God." Just as parents pass the gift of life from generation to generation, the gift of grace is passed on with each person's rebirth through baptism, he said.