Mary's response to the angel Gabriel's message is amazing. She simply said "Yes, I am the Lord's servant." When we read about God's call to people in the Old Testament, some made excuses. Other asked God to give them a sign to prove He was really calling them to service. Some even asked God to send someone else. Jonah tried to run away from God's call. Despite their objections, God continued to call them into His service.
Mary said yes, even though it meant putting her marriage to Joseph, her reputation and maybe even her life at risk. She became the mother of Jesus Christ, the Promised Savior.
It may not be easy to say "Yes" when God calls, but it is never a good idea to say "No" to God.