The Easter Vigil is the “Mother of All Vigils. “Easter Sunday, then, is the greatest of all Sundays, and Easter Time is the most important of all liturgical times.  Easter is the celebration of the Lord’s resurrection from the dead, culminating in his Ascension to the Father and sending of the Holy Spirit upon the Church.  There are 50 days of Easter from the first Sunday to Pentecost.  It is characterized, above all, by the joy of glorified life and the victory over death, expressed most fully in the great resounding cry of the Christian: Alleluia!  All faith flows from faith in the resurrection: “If Christ has not been raised, then empty is our preaching; empty, too, is your faith.” (1 Cor 15:14)

— U.S. Conference of Catholic Bishops