So all through the great persecutions of the first three centuries, year by year – indeed Sunday by Sunday – the Christians met in peril of their lives to celebrate the salvation won by the Crucified and Risen Christ, that salvation which has always been the central pivot of the whole Christian religion.  For upon the Crucifixion and Resurrection of Christ hang our deliverance from the power of evil, our restoration to God, our union with him and all our hope of eternal life.

When the persecutions ended and pilgrimages to the Holy Places in Palestine became safe and frequent, the custom arose of commemorating the events of Holy Week and Easter approximately on the actual sites and at the actual times of their original occurrence.  That was in the fourth century, but another 100 years were to pass before the same observance was adopted elsewhere.