Luke is fond of telling stories of faith. In his stories Luke narrates scenes in which trust in the spoken word from God is the very essence of faith.
It all begins with an old priest named Zechariah. This is the first story that Luke tells us in his Gospel. One day, Luke writes, the lot fell to Zechariah to enter the temple of the Lord and burn incense. As he was about to perform this sacred task, however, an angel of the Lord appeared to him standing just to the right of the altar. Zechariah was troubled. Fear fell upon him. The angel spoke words of comfort to Zechariah. "Do not be afraid, Zechariah," the angel said, "for your prayer has been heard. Your wife Elizabeth will bear you a son, and you will name him John" (Luke 1:13). The angel Gabriel went on to announce to Zechariah that his son John would be filled with the Holy Spirit and would make the way ready for the Messiah to come. Zechariah had heard a word spoken to him from God. Zechariah had heard a word from Gabriel announcing new realities that were to come to pass.
Of such stuff is faith composed as Luke tells the story. Faith, or unfaith! Zechariah heard the word from God. He did not believe it! "How will I know that this is so?" Zechariah demanded of the angel (Luke 1:18). "I'm an old man and my wife is old too. How can this word be?" "I am Gabriel," the angel shot back. "How will I know?" said Zechariah. "I am Gabriel," came the reply. And the angel continued. "... because you did not believe my words, which will be fulfilled in their time, you will become mute, unable to speak, until the day these things occur" (Luke 1:20). "You did not believe my words." That is the heart of Zechariah's unbelief. Mary is next in line. Six months into Elizabeth's pregnancy Gabriel spoke words from God to Mary. "Hail, O favored one, the Lord is with you" (Luke 1:28).
That was Gabriel's greeting to Mary. Like Zechariah before her, Mary was troubled and afraid at the sound of the angel's voice. Gabriel spoke to her as he had spoken to Zechariah: "Do not be afraid, Mary, for you have found favor with God. And now, you will conceive in your womb and bear a son, and you will name him Jesus" (Luke 1:31). Mary, like Zechariah, heard a word spoken to her from God. Mary, too, is unsure. "How can this be," she protests, "since I am a virgin?" (Luke 1:34). Gabriel told Mary that it will be because the Holy Spirit will make it happen. Mary was satisfied. She spoke great words of faith. "Here I am," she said, "the servant of the Lord; let it be with me according to your word" (Luke 1:38). "You did not believe my words," said Gabriel to Zechariah. That is the heart of Zechariah's unfaith. "...let it be with me according to your word," were Mary's words to Gabriel. This is the heart of Mary's faith.
Faith is called into being by a word spoken from God. A centurion in Capernaum grasped this reality very well. "Only say the word ...," the centurion said. Luke presents this rather unlikely fellow, this centurion, this stranger to Israel, this foreigner as a model of faith. "Only say the word ...."