Zechariah asked the angel, “How can I be sure of this? I am an old man and my wife is well along in years.”
“I am the Lord’s servant,” Mary answered. “May your word to me be fulfilled.” -Luke 1:18,38 NIV
The angel Gabriel made two visits that year. One was to a religious leader and one to a teenage girl. These had very different responses to the angel. The older, "wiser", one had unbelief while the younger, "naive" one, had faith. It seems to me that the older responded from his mind and the younger from her heart. It speaks to me of how faith is a matter of the heart. It tells me that angelic messages, the good news, must be heard with the heart and not the head.
... this devotion is part of an ongoing Advent series.