First century Christians liked pretending that Jesus lived his life all over again every year from Christmas to the Ascension. They liked to think of the Magi coming again at Epiphany, of Jesus dying on Good Friday, of Christ rising on Easter.
They did a special thing for Holy Saturday: they prepared a pool of water that had a double purpose. For one thing it was their baptistery, for another it represented the tomb of Jesus. That made their going down into that pool a sharing in his death. They very much had in mind St. Paul’s teaching that what made the death of Jesus efficacious was that it was a death to sin.
Whatever might have been uppermost in the mind of each candidate going down into the pool, the act itself was symbolically stating, “This baptism is my pledge to die to sin with Christ.”
In a large room adjoining the place for Baptism, the Christians were setting up the altar for the Easter morning Mass. (It will be the first full Mass in which the newly baptized would have been able to take part.)
As each newly baptized Christian was passing from the baptistery to the church he or she was briefly met by the bishop. Anointing the forehead of each with chrism, the bishop would pray that the Holy Spirit would enter into possession of each heart vacated by Satan. That was the Sacrament of Confirmation.
But the Easter ceremony was not for just the newly baptized.
No Creed is recited on Easter, because it is replaced by the baptismal vows made by all present. The resolve to die to sin and to live to God is as important for everyone there as it is for the newly baptized.
The whole purpose of Lent is to put us into fine spiritual shape so that we will be able to carry out our baptismal vows. For us the whole purpose of Easter is that we might live again with Christ.