It was prophesied 4 millenniums earlier and numerous times between. Gen. 3:15, Isa. 7:14; 9:6, Micah 5:2.
It was a biological miracle, no male involved! Matt. 1:18 says, "Now the birth of Jesus Christ was on this wise: When as his mother Mary was espoused to Joseph, before they came together, she was found with child of the Holy Ghost."
In Luke 1:35, the angel told Mary: "The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee: therefore also that holy thing which shall be born of thee shall be called the Son of God."
In Matt. 1:20, the angel told Joseph, "...for that which is conceived in her is of the Holy Ghost." Mary, the mother of Jesus wasn't touched by man until after the birth of Jesus! Matt. 1:25 says Joseph "knew her not till she had brought forth her firstborn son: and he called his name JESUS."
According to Isa. 9:6, the Child born is the Mighty God! In Matt. 1:23, He is "Emmanuel, which is being interpreted, God with us."
God was born in flesh to be the Saviour! Luke 2:10-11: "And the angel said unto them, Fear not: for, behold, I bring you good tidings of great joy, which shall be to all people. For unto you is born this day in the city of David a Saviour, which is Christ the Lord."
Since he was born to be the Saviour; He had to be God; He had to be sinless; He could not have a sinful nature; He was free from the curse of sin because He did not have a human, earthly, sinful, fleshy father! Notice Matt. 2:13, 14, 20, 21 in speaking to Joseph, "young child and His mother" is used four times! The reason for this is HE IS NOT JOSEPH'S SON! HE IS THE CHILD OF THE HOLY GHOST! To further blow the theology of Christ-rejecting people who deny the virgin birth, Micah 5:2 says, "But thou, Bethlehem Ephratah, though thou be little among the thousands of Judah, yet out of thee shall he come forth unto me that is to be ruler in Israel; whose goings forth have been from of old, from everlasting."!!!
A belief in the incarnation of Christ is necessary for salvation! Read 2 John 7-11 and notice: ..."who confess not that Jesus Christ is come in the flesh..." and verses 10-11, "If there come any unto you, and bring not this doctrine, receive him not into your house, neither bid him God speed: For he that biddeth him God speed is partaker of his evil deeds."
True Bible salvation is impossible apart from faith in the Virgin birth of Jesus Christ. Have you received Him as your own personal Lord and Saviour? 1 Tim. 3:16. Do you believe He is God? God the Son died on the cross for you and I. Receive Him today!