Matthew 1:18 - 24

18 Now the birth of Jesus Christ was as follows: After His mother Mary was betrothed to Joseph, before they came together, she was found with child of the Holy Spirit. 19 Then Joseph her husband, being a just man, and not wanting to make her a public example, was minded to put her away secretly. 20 But while he thought about these things, behold, an angel of the Lord appeared to him in a dream, saying, “Joseph, son of David, do not be afraid to take to you Mary your wife, for that which is conceived in her is of the Holy Spirit. 21 And she will bring forth a Son, and you shall call His name Jesus, for He will save His people from their sins.”

22 So all this was done that it might be fulfilled which was spoken by the Lord through the prophet, saying: 23 “Behold, the virgin shall be with child, and bear a Son, and they shall call His name Immanuel,” which is translated, “God with us.”

24 Then Joseph, being aroused from sleep, did as the angel of the Lord commanded him and took to him his wife, 25 and did not know her till she had brought forth her firstborn Son. And he called His name Jesus.

In the days of Christ, being betrothed, or engaged as we would say, was as much of a commitment as being married.

Before Mary and Joseph began living together, she was found to be pregnant with Jesus, this could have been a sinful and shameful condition, but she had not done anything wrong, she had been impregnated by the Holy Spirit.

Mary was pregnant, not with Joseph's child, he was the groom. He had the option being a fair man that he could have broken the engagement quietly and not have put her through the disgrace of making a spectacle of her condition. But he did not feel it was right to go on with the marriage.

While Joseph was considering what to do, an angel of the Lord appeared to him and explained the situation. He told Joseph to continue with the marriage because Mary was innocent of any wrong doing. Mary is called his wife, and Luke 2:5 called “his espoused wife.” This is because an engagement was as binding as a marriage is today.

The angel told Joseph what to name the baby, in those days names had specific meanings, Jesus meant Savior because he was destined to save his people from sin.

Joseph was told by the angel that this event would fulfill scriptural prophecy, and since he was a believing Jew he believed.

The angel refers to Isaiah 7:14 born of a virgin indicates a miraculous birth and the child's name meaning “God with us” indicates Christ was both divine and human, Emmanuel because he was God in the presence of man.

Being aroused from sleep indicates the angel came to Joseph in a vision or a dream. After he woke he did as the angel had instructed him, he married Mary.

He did not have sexual relations with Mary until after Jesus was born to allow the prophecy of being born to a virgin to be true. They continued to live together as husband and wife and have children which we will meet later in this book. Jesus is listed in this passage as Mary's firstborn son, if she had only Jesus then he would have been her only son, not just her firstborn son.