Now the birth of Jesus Christ was as follows: when His mother Mary had been betrothed to Joseph, before they came together she was found to be with child by the Holy Spirit. And Joseph her husband, being a righteous man and not wanting to disgrace her, planned to send her away secretly.
But when he had considered this, behold, an angel of the Lord appeared to him in a dream, saying:
Joseph, son of David, do not be afraid to take Mary as your wife; for the Child who has been conceived in her is of the Holy Spirit. She will bear a son; and you shall call His name Jesus, for He will save His people from their sins.
Matthew's Gospel, 1:18-21