“[Faith] sees in the resurrection of Christ not the eternity of heaven, but the future of the very earth on which his cross stands. It sees in him the future of the very humanity for which he died. That is why it finds the cross the hope of the earth.” -Jürgen Moltmann (Theology of Hope, 21)The resurrection is what gives meaning to the crucifixion of Jesus and the crucifixion is what gives meaning to the resurrection. The reason that Christ's presence in solidarity with crucified people on the cross has any light, even in its undeniable darkness, is because this Jesus has resurrection as his future. And the reason that resurrection has any importance beyond a mere miracle of human biology is because it is the resurrection of the one who united divinity to humanity, even crucified humanity. It is the resurrection of him who has met us in the deepest darkness, and who "humbles himself and takes upon himself the eternal death of the godless and the godforsaken, so that all the godless and the godforsaken can experience communion with him" (Moltmann, The Crucified God). In communion with him, as he shares our fate, we share his future. Therefore, when we witness the resurrected Jesus, we witness a future reality, our future reality, and our true nature. Resurrection is, because of who God is, the only natural consequence of God's crucifixion in Jesus, for God is indeed that whom God is becoming. God is God's future. And being brought into communion with God through hypostatic union, through Christ's gracious communion with us--even in death--we are made to share this future as our revealed nature. We are God's future. And God's future is resurrection.
As Carl Ullmann put it,
"The resurrection of Christ in particular...appears but as the natural and necessary consequence of the divine life which filled the constitution of his person; while it forms besides, in virtue of the life bond that unites him with his people, the ground of the whole Christian eschatology as connected with the resurrection of believers" (Carl Ullmann, "On The Distinctive Character of Christianity" in John Williamson Nevin's The Mystical Presence, 37).
When we behold the risen Christ, in our communion with him in his death, we behold the truth about ourselves, the truth about our world, and we are compelled to leave in the grave all that which does not belong to this resurrected life.