Christ is risen from the dead, trampling down death by death, and upon those in the tombs bestowing life!
The celebration of Pascha (called "Easter Sunday" in the West) in the Orthodox Church is not merely a historical re-enactment of Christ's Resurrection as narrated in the gospels. It is not a dramatic presentation of "the first Easter morning," and there is no "sunrise service", since the Paschal Matins and Liturgy are celebrated together in the first dark hours of the first day of the week in order to give men the experience of the new creation of the world, and to allow them to enter mystically into the New Jerusalem which shines eternally with the glorious Light of Christ!
The Church teaches that while the body of Christ rested in the tomb on the Sabbath (the day after the Crucifixion), His soul descended into Hades. Prior to the Incarnation, the gates of paradise were closed to mankind. Therefore Hades, not to be confused with Hell, was the place where the souls of all went upon death. It was neither a place of reward, nor a place of punishment. It had been likened to "Death's prison", where the souls of both the just and the sinners were confined. Since Christ actually died upon the Cross, Death claimed His Soul for Hades. However, Hades received more than it expected… it received the Giver of Life, who destroyed the power of Hades. The icon of the Resurrection portrays this concept.