What does Luke 1:30 mean?

Gabriel's reassurance to Mary (Luke 1:26–27) addresses the natural fear a person might suffer when confronted with a powerful angel (Luke 2:10; Matthew 28:4; Acts 10:3–4). It also repeats part of his initial greeting (Luke 1:28) and eases her anxiety about what God is about to expect of her (Luke 1:29). Her role will be relatively passive, but incredibly important. Being chosen for this function in God's plan is a great honor and blessing: Mary is "highly favored," indeed.

Mary's role will fulfill prophecy. The Child she bears will be Jesus Christ, the Messiah, and the Son of God (Luke 1:31–33). Mary is a virgin, who has never been intimate with any man (Luke 1:34), matching predictions that the Promised One would be virgin-born (Isaiah 7:14). Both Mary (Luke 3:23–38) and her husband (Matthew 1:1–17) are part of the house of David. This is the family from which the Lord said the Savior would come (2 Samuel 7:12–16; Isaiah 9:6–7).