"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. Then Joseph her husband, being a just man, and not wanting to make her a public example, was minded to put her away secretly. 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. And she will bring forth a Son, and you shall call His name JESUS, for He will save his people from their sins'" (Matt. 1:18-21).
Matthew has yet to prove that Jesus is the Christ, but he continues to build His case. Thus far he has shown that Jesus is a descendent of David and Abraham. He now tells of Jesus' birth in order to establish Jesus as the "Son of God" (Matt. 16:16). His mother, Mary, was betrothed to Joseph, but before they "came together" (i.e., had sexual relations), she became pregnant. Thus, this child is obviously not Joseph's; rather, it is "of the Holy Spirit." Her pregnancy was likely discovered soon after her return from visiting Elizabeth.
The three steps usually taken in Jewish marriages were:
Joseph has understandably assumed that Mary has been unfaithful to him. He is undoubtedly in a difficult situation, as is Mary. But, an angel of the Lord appeared to him in a dream and began explaining what had happened to Mary. He first tells Joseph not to be afraid. There are two things that Joseph might be afraid of: (1) The ridicule from others by accepting a woman who appeared to be a fornicator & (2) marrying a woman who might be untrue to him again. After learning the truth from this dream, Joseph would no longer fear these two things. Of course, he now had other things to be concerned about--namely, the tremendous responsibility and privilege of rearing the Messiah!
Mary's baby would be a son and would be named Jesus "for he will save His people from their sins." This briefly expresses the mission of Jesus (cf. Luke 19:10). The great task before Him is to save "His people" from the bondage of sin. Hence, He is to be a Savior. His purpose would not be to deliver Israel from Roman bondage or to establish an earthly kingdom, but He is to save the people from their sins! This was God's plan from the beginning (cf. Rev. 13:8)!
We will continue studying this passage in our next lesson.