The Responsorial Psalm (Psalm 24) invites us to open our hearts to the Son of God: "Let the Lord enter; he is the king of glory."
But only by the power of God can we open ourselves to the mystery that God offers us: "the grace of our Lord Jesus Christ," which is the favor of sharing in God's own divine life. And so in the O Antiphon we call out: "O Key of David, opening the gates of God's eternal Kingdom, come and free the prisoners of darkness."
In Isaiah 7: 10-14 Ahaz was afraid to ask for a sign from God. And in Luke 1: 26-38 Mary was "troubled" because the angel called her "highly favored" and "blessed among women." There is something in us that is afraid to believe God could be blessing us - or even dealing with us - in a special, personal way.
We find it hard to believe that God is calling us by name to do some great work, or blessing us with more than the help to live ordinary, good human lives. It shocks us when St. Augustine says, "We have become Christ." It shocks us more to read in the Liturgy of the Hours, "Those who by faith are spiritual members of Christ can truly say that they are what he is: the Son of God and God himself!" (Blessed Isaac of Stella, Friday reading, fifth week of Easter). Some theological precision follows: "What Christ is by nature we are as his partners; what he is of himself in all fullness, we are as participants. Finally, what the Son of God is by generation, his members are by adoption." But the precision is just qualification of the basic fact: that by "the grace of our Lord Jesus Christ" we become divine. "Our nature is transformed so that we are no longer merely humans, but also sons of God, spiritual people, by reason of the share we have received in the divine nature" (St. Cyril of Alexandria, bishop, Tuesday reading, second week of Easter).
Why is it so hard for us to accept the mystery of our being? Is it because we don't want the responsibility of living on the level of God? Would we rather forget, in the daily decisions and activities of life, that we are the body of Christ?
The truth is, to accept to be Christian is to accept to be Christ! Have I accepted this? Am I willing to "offer my body" every day as a living sacrifice" (Romans 12:1) so that Christ can act with me, in me and through me in all I do?
Mary said to the angel: "Let it be with me according to your word," and gave her body. This is what we are asked to do.
"Let the Lord enter; he is the king of glory?"