The glory of Easter is the heart of the Christian gospel. It is the centre of the Church's faith and worship. In the earliest days of the Church it was the only Christian festival: an annual celebration, in one act, of Christ's life, death, resurrection, ascension, and his sending of the Holy Spirit. The celebration lasted fifty days in one continuous festival of adoration, joy, and thanksgiving, ending on the Feast of Pentecost.
By the fourth century, the Church was adding to its celebration of Easter a week-long commemoration of the events which preceded our Lord's resurrection, beginning on Sunday with his triumphal entry into Jerusalem.
Christians would recall the final meal Jesus had with his disciples and his institution of the sacrament of the eucharist. On the Friday they would commemorate Christ's agony and death on the cross.
On Saturday night they would gather for the reading of the scripture, for prayers, for the baptism of their new converts, and then, as the day of the resurrection dawned, for the joyful celebration of Easter.
The week before Easter became known as Holy Week. The focal points of this week would be The Sunday of the Passion with the Liturgy of the Palms,
- Maundy Thursday, with foot washing and a thanksgiving for the institution of the eucharist,
- Good Friday, with a veneration of the cross,
- Easter Eve, with the Great Vigil, paschal fire, initiation, and the Easter eucharist.
BAS p. 296