Several years ago I did a reflection for my parish. I noted that all through Advent we sing Veni, Veni, Emmanuel, and pray that God will come and really reveal Godself as Emmanuel, the God who is with us. I also noted that we may not always realize the depth of meaning captured in the name Emmanuel. We may not realize, for instance, the degree of solidarity with us and the whole of creation it points to.
There are several reasons for our failures here. First, we tend to use Emmanuel only during Advent and Christmastide so we stop reflecting on the meaning or theological implications of the name. Secondly, we are used to thinking of a relatively impersonal God borrowed from Greek philosophy; he is omnipresent -- rather like air is present in our lives and he is impassible, incapable of suffering in any way. Because he is omnipresent, God seems already to be "Emmanuel" so we are unclear what is really being added to what we know (and what is now true!!) of God. Something is similarly true because of God's impassibility which seems to make God incapable of suffering with us or feeling compassionate toward us. (We could say something similar regarding God's immutability, etc. Greek categories are inadequate for understanding a living God who wills to be Emmanuel with all that implies.) And thirdly, we tend to forget that the word "reveal" does not only mean "to make known," but also "to make real in space and time." The eternal and transcendent God who is revealed in space and time as Emmanuel is the God who, in Christ, enters exhaustively into the most profoundly historical and personal lives and circumstances of his Creation and makes these part of his own life in the process.
Thus, just as the Incarnation of the Word of God happens over the whole of Jesus' life and death and not merely with Jesus' conception or nativity, so too does God require the entire life and death of Jesus to achieve the degree of solidarity with us that makes him the Emmanuel he wills to be. There is a double "movement" involved here, the movement of descent and ascent, kenosis and theosis. Not only does God in Christ become implicated in the whole of human experience and the realm of human history but in that same Christ God takes the whole of the human situation and experience into Godself. We talk about this by saying that through the Christ Event heaven and earth interpenetrate one another and one day God will be all in all or, again, that "the Kingdom of God is at hand." John the Evangelist says it again and again with the language of mutual indwelling and union: "I am in him and he is in me," "he who sees me sees the one who sent me", "the Father and I are One." Paul affirms its dimensions in Romans 8 when he exults, "Nothing [at all in heaven or on earth] can separate us from the Love of God."
And so, in Jesus' life and active ministry, the presence of God is made real in space and time in an unprecedented way --- that is, with unprecedented authority, compassion, and intimacy. He companions and heals us; he exorcises our demons, teaches, feeds, forgives and sanctifies us. He is mentor, brother, and Lord. He bears our stupidities and fear, our misunderstandings, resistance, and even our hostility and betrayals. But the revelation of God as Emmanuel means much more besides; as we move into the Triduum we begin to celebrate the exhaustive revelation, the exhaustive realization of an eternally-willed solidarity with us whose extent we can hardly imagine. In Christ and especially in his passion and death God comes to us in the unexpected and even the unacceptable place. Three dimensions of the cross especially allow us to see the depth of solidarity with us that our God embraces and achieves in Christ: failure, suffering unto death, and lostness or godforsakenness. Together they reveal our God as Emmanuel --- the one who is with us as the one from whom nothing can ever ultimately separate us because in Christ those things become part of God's own life.
Jesus comes to the cross ostensibly having failed in his mission. (From one perspective we could say that had he succeeded completely there would have been no betrayal, no trial, no torture, and no crucifixion.) Jesus had spoken truth to power all throughout his ministry. On the cross, this comes to a climax and in the events of Jesus' passion, the powers and principalities of this world appear to swallow him up. But even as this occurs and Jesus embraces the weight of the world's darkness and deathliness, Jesus remains open to God and trusts in his capacity to redeem any failure; thus even failure, but especially this one, can serve the Kingdom of God. Jesus suffers to the point of death and suffers more profoundly than any person in history we can name --- not because he hurt more profoundly than others but because he was more vulnerable to it and chose to embrace that vulnerability and all the world threw at him without mitigation. Suffering per se is not salvific, but Jesus' openness and responsiveness to God (that is, his obedience) in the face of suffering is. Thus, suffering even unto death is transformed into a potential sacrament of God's presence. Finally, Jesus suffers the lostness of godforsakenness or abandonment by God --- the ultimate separation from God due to sin. This is the meaning of not just death but death on a cross. In this death, Jesus again remains open (obedient) to the God who reveals himself most exhaustively as Emmanuel and takes even the lostness of sin and death into himself and makes these his own. After all, as the NT reminds us, it is the sick and lost for whom God in Christ comes.
As I have noted before, John C. Dwyer, my major Theology professor for BA and MA work back in the 1970's described God's revelation of self on the cross (God's making himself known and personally present even in those places from whence we exclude him or believe he should never be found) --- the exhaustive coming of God as Emmanuel --- in this way:
[[Through Jesus, the broken being of the world enters the personal life of the everlasting God, and this God shares in the broken being of the world. God is eternally committed to this world, and this commitment becomes full and final in his personal presence within this weak and broken man on the cross. In him the eternal One takes our destiny upon himself --- a destiny of estrangement, separation, meaninglessness, and despair. But at this moment the emptiness and alienation that mar and mark the human situation become once and for all, in time and eternity, the ways of God. God is with this broken man in suffering and in failure, in darkness and at the edge of despair, and for this reason suffering and failure, darkness and hopelessness will never again be signs of the separation of man from God. God identifies himself with the man on the cross, and for this reason everything we think of as manifesting the absence of God will, for the rest of time, be capable of manifesting his presence --- up to and including death itself.]]
He continues,
[[Jesus is rejected and his mission fails, but God participates in this failure, so that failure itself can become a vehicle of his presence, his being here for us. Jesus is weak, but his weakness is God's own, and so weakness itself can be something to glory in. Jesus' death exposes the weakness and insecurity of our situation, but God made them his own; at the end of the road, where abandonment is total and all the props are gone, he is there. At the moment when an abyss yawns beneath the shaken foundations of the world and self, God is there in the depths, and the abyss becomes a ground. Because God was in this broken man who died on the cross, although our hold on existence is fragile, and although we walk in the shadow of death all the days of our lives, and although we live under the spell of a nameless dread against which we can do nothing, the message of the cross is good news indeed: rejoice in your fragility and weakness; rejoice even in that nameless dread because God has been there and nothing can separate you from him. It has all been conquered, not by any power in the world or in yourself, but by God. When God takes death into himself it means not the end of God but the end of death.]] Dwyer, John C., Son of Man Son of God, a New Language for Faith, p 182-183.