Why wouldn't she have been afraid? She'd likely not seen an angel before. The unearthly being brought a personal message that would change her life.
But God's word through Gabriel also calmed her. I'm sure the Scripture had become part of her mental and emotional fabric. She would have memorized much of it through hours of study and meditation. Because she lived in God’s presence, she could recognize God’s voice however it came.
Mary's heart and intellect were so given to God that her dialogue with Him was authentic and precious to them both. Now she was about to enter a phase of obedience that would challenge, delight, and tear her heart and mind.
God's perfect love comes, whether heralded by an unfamiliar angel or by a familiar scriptural phrase, and His presence reminds us, Do not be afraid.
FOR YOUR CONSIDERATION
As you prepare for Advent, examine yourself for any fear you might have and why. Talk to Immanuel, and listen for the Holy Spirit who comes to you through the Scriptures or circumstances. How could you address your fear [or grief] together?
Meditate on 1 John 4:16-18 (NIV)
God is love. Whoever lives in love lives in God, and God in him. 17 In this way, love is made complete among us so that we will have confidence on the day of judgment, because in this world we are like him. 18 There is no fear in love. But perfect love drives out fear, because fear has to do with punishment.
Thank God for the perfect love He shows us through His beloved, Jesus Christ.