Mary was told by Gabriel she was blessed and highly favored. She wondered about that greeting.
“Then the angel said to her, ‘Do not be afraid, Mary, for you have found favor with God. And behold, you will conceive in your womb and bring forth a Son, and shall call His name JESUS. He will be great, and will be called the Son of the Highest, and the Lord God will give Him the throne of His father David. And He will reign over the house of Jacob forever, and of His kingdom there will be no end.”
He was telling her that her son would be the promised Savior and would be King forever. Notice she did not comment upon all that, but instead, asked how she could become pregnant:
“Then Mary said to the angel, “How can this be, since I do not know a man?”
Mary was a virgin. She had never had a sexual relationship with anyone. Not even with Joseph with whom she had made known a serious intent to marry. So how could she have a son, any son, much less the “promised one?”
“The Holy Spirit will come upon you, and the power of the Highest will overshadow you; therefore, also, that Holy One who is to be born will be called the Son of God.” (Luke 1: 30-35)
As myterious as this sounded, Mary evidently believed it. We’re not told if she knew when it happened, but by the time, she arrived to visit her relative, Elizabeth, she was pregnant. Her sexual purity was a big thing–the virgin birth of Jesus was a mark, a sign, of his being the promised Savior.
Isaiah’s prediction, in Isaiah 7:14, that a virgin would have a baby and would call him “God With Us”–Immanuel–had been a matter of debate and interpretation for 700 years. Now, in Matthew 1:23, the apostle applies that prophecy to Mary and Jesus specifically. This was the sign that set Jesus apart from all the rest: He was the child of a virgin, born like the rest of us. He was God With Us just as Isaiah had predicted.
It is so important to keep this all in your mind as you read about the judgments in Isaiah, and the Judgment Day to come so that you get the right picture of God. His judgment is real, but His compassion shines through in providing a Savior.
Mary pondered all these things–she kept them in her heart.