VATICAN CITY — Pope Francis baptized 21 babies in the Sistine Chapel on Sunday under the ceiling frescoed by Michelangelo, in what has become an annual tradition that marks the end of the Christmas holiday period at the Vatican. Francis celebrated the Lord’s gift of faith to the children, stressing they were the protagonists of the ceremony. “It is important that these children feel well,” the pope said. “If they are hungry, feed them so they don’t cry. If they feel hot, change them. … But let them feel at ease, because today they are in charge and we must serve them with the Sacrament, with prayers.” The pontiff personally administered the sacrament of baptism on the infants, who are the children of Vatican employees working at the Holy See. The celebration marks the feast day that recalls Jesus’ baptism in the River Jordan and was established in 1981 by St. John Paul II. During the ceremony, each father was given a candle to light representing the Christian light that “must never go out.” The Pope encouraged each family to bring those candles home and light them up in difficult times to ask for the Lord’s guidance.