Jesus and Mary both share one trait- they are both pure and stainless at the time of His birth.
Jesus is both Holy (concevied by the Holy Spirit) and human by birth.
Only a virgin could have birthed the One who is sinless and withouth blemish.
That is vital to our Christian walk!
Mary would conceive a son
His name is Jesus
He will be great
He will be called the son of God
He will reign over Israel,
God will give him the throne of David
His Kingdom will never end