Matthew 1:18-21

18: This is how the birth of Jesus Christ came about: His mother Mary was pledged to be married to Joseph, but before they came together, she was found to be with child through the Holy Spirit.
19: Because Joseph her husband was a righteous man and did not want to expose her to public disgrace, he had in mind to divorce her quietly.
20: But after he had considered this, an angel of the Lord appeared to him in a dream and said, "Joseph son of David, do not be afraid to take Mary home as your wife, because what is conceived in her is from the Holy Spirit.
21: She will give birth to a son, and you are to give him the name Jesus, because he will save his people from their sins."