The Easter Vigil began in the atrium of the basilica with the blessing of the new fire and the lighting of the paschal candle, symbol of Christ, "Light of the World."
The Pope then crossed the central nave of the basilica, while darkness gave way to dazzling light.
"The light of him who 'has been raised from the dead, the first fruits of those who have fallen asleep' makes this memorable night 'bright as the day,'" the Holy Father said later during the homily of the Mass, concelebrated by 24 cardinals and numerous bishops.
Seeing that the seven catechumens were from Italy, Togo and Japan, the Pope said that this variety of origins "manifests the universality of the call to salvation and the gratuitousness of the gift of faith."
"Thanks to the sacrament of baptism, you will come to be a part of the Church, which is an immense people on pilgrimage, without limits of race, language or culture; a people called to the faith starting with Abraham, and destined to become a blessing in the midst of all the nations of the earth," he added with difficulty due to fatigue.
Conscious of Christ's promise -- "I am with you always, to the close of the age," the Pope encouraged the catechumens not to be afraid when living the Christian life.
"His word will enlighten you," the Holy Father added. "His Body and Blood will nourish you and sustain you on your daily journey to eternity."