We are seeing several texts from Revelation in Easter. It makes sense from the perspective of Jesus as the first fruits of those who have died and from the perspective of his resurrection as the beginning of a whole new age.
In Pilgrim at Tinker Creek, Annie Dillard writes, "The lone ping into being of the first hydrogen atom ex nihilo was so unthinkably, violently radical that surely it ought to have been enough, more than enough. But look what happens: you open the door and all heaven and hell break loose" ([Bantam Books, 1974] 134).
The same is true of the empty tomb. After Christ is risen, no dream is too big. God opens that tomb and look what happens: it is not just Christ's life but also Mary's life that is restored. And that is just the beginning. God opens the tomb and the Jewish fisherman Peter finds himself saying to the Roman centurion Cornelius and his household, "I truly understand that God show no partiality, but in every nation anyone who fears him and does what is right is acceptable to him" (Act. 10:34f). God opens that tomb and John of Patmos sees a new heaven and a new earth breaking loose, where death will be no more; mourning and crying and pain will be no more, for the former things have passed away" and where the one seated on the throne says, "See, I am making all things new" (Rev. 21:4-5). Before Easter, none of these witnesses to new life would have made sense. After Easter, they begin to.