Jesus' birth is a mystery. The Word of God became flesh. It was an event that went unnoticed on earth, even though all of heaven resounded in glory at his birth. He was born to atone for the sin of the world. God's Word became flesh and blood to take away the sin of the world. Other than his resurrection from the dead, it is the most significant event in human history.
This mystery is what the church is sent into the world to proclaim: glad tidings of joy for all men. But what have we done with the mysteries of God in recent years? What have we, as the stewards of the mysteries of God, done with the message of the incarnation? Have we abandoned our mission? Did we lose the mystery? Where has the evangelical proclamation of the Reformation gone?
In the nineteenth century, enlightened people decided that the mystery of God's incarnation wasn't reasonable or plausible. So they undertook to eliminate the mystery of God from pulpits, liturgy, and catechesis. As Lutheran theologian Hermann Sasse said: "The confession of the church was stripped like a Christmas tree. Nothing useful was really left except an old bit of wood. "He was conceived by the Holy Spirit and born of the virgin Mary" (Hermann Sasse, Sermon for the 3rd Sunday in Advent).
We discarded the mystery of God's Word becoming flesh, Jesus' death on the cross for the sin of the world, and his resurrection from the dead. Afterward, the twentieth-century churches reaped the fruit of this rejection of God's incarnation. Now, we celebrate Christmas as thousands of churches have permanently closed or are slowly dying because they've neglected the mysteries of God.
But God is faithful and just, and he will not abandon his people. He came to a world unaware of his birth, but his faithfulness to his promises will not cease because of our unbelief. Jesus Christ is not a private, personal Savior of sinners. He's a public, proclaiming for all to hear, Savior of sinners. He will protect his church from sin, death, and Satan. He will gather up his people just like a mother gathers her children around her as she reads about the Nativity of our Lord from Luke's Gospel.
Christmas-time is the bold proclamation that God was born to save sinners; Jesus came to save lost causes like you and me. This is the great mystery at the heart of our Christmas proclamation. That's why we have a future, even as church bells stop ringing across our nation.
Christmas is the proclamation that "to us, a child is born, to us a son is given; and the government shall be upon his shoulder, and his name shall be called Wonderful Counselor, Mighty God, Everlasting Father, Prince of Peace" (Isa 9:6).
That's why Jesus' birth is a mystery. The Word of God was born of a Virgin. He was born to atone for the sin of the world. God's Word became flesh and blood to take away the sin of the world. In the mystery of this proclamation, God has given us a future so that we "may be his own and live under him in his kingdom and serve him in everlasting righteousness, innocence, and blessedness, just as he is risen from the dead, lives and reigns to all eternity" (Martin Luther, Small Catechism II, 2).