The angel answered her, “The Holy Spirit will come upon you, and the power of the Highest will overshadow you. Therefore the Holy One who will be born will be called the Son of God.”
— Luke 1:35
The Virgin Birth is clearly taught repeatedly throughout the Old Testament and the New Testament in many different kinds of ways.
Once there was a newly minted young minister in a rural area. And there was a man in the neighborhood, an old farmer who didn’t attend church. One Christmas season he invited him to come. And the man agreed. The sermon was on the Virgin Birth. As they were discussing the sermon afterwards, the minister asked the farmer what he thought. (I have learned the hard way that is a big mistake for a pastor to make.) The farmer hemmed and hawed. Finally he said, “Well, now, my boy,” he said, “Let me ask you a question. If you heard about a girl today that got herself pregnant and then claimed that it was a virgin birth, would you believe that?”
Another silence. And the young man said, “Well, if he grew up to live a life like Jesus and came to die and rise from the dead, why yes, I would.”