Who is Emmanuel?
We hear a lot about "Emmanuel" at Christmas, but who is Emmanuel? The word Emmanuel appears 3 times in the Bible - twice in Isaiah and once in Matthew. Emmanuel means "God with us" and is a name for Jesus.
The word "Emmanuel"
The word "Emmanuel" comes from the Greek rendering of two Hebrew words, `immanu, "with us," and 'el, "God" (thus in English it is found as either "Emmanuel" or "Immanuel"). The word is found three times in the Bible: Isaiah 7:14, 8:8, and Matthew 1:23 (it is present in Isa 8:10 as well, but there it is used to say "God is with us," not as a proper name). It is found only once in the New Testament, toward the end of the birth narrative of Jesus in the Gospel of Matthew. Here Matthew is citing Isaiah 7:14, and the word is the Greek rendering of the Hebrew word from the Old Testament. Matthew says that the birth of Jesus by the virgin Mary is to "fulfill what the Lord had spoken by the prophet: 'Behold, the virgin shall conceive and bear a son, and they shall call his name Immanuel' (which means, God with us)" (1:22-23). Thus, Matthew tells his readers that Jesus' birth fulfills the prophecy of Isaiah and goes on to explain what the word "Emmanuel" means, "God with us." To understand this further we must examine the origin of the word in Isaiah.
"Emmanuel" in Isaiah
Isaiah 7:14 is the first place the word appears in the Bible. Here the Lord speaks through Isaiah the prophet to Ahaz, king of Judah. At this time in Israel's history, the land was divided between the northern and southern kingdoms (the northern kingdom was often designated "Israel" and the southern "Judah"). Ahaz is afraid because the northern kingdom has joined forces with the neighboring land of Syria, and he believes they will seek to destroy him and his people. But God tells him, "It shall not stand, and it shall not come to pass" (7:7). Ahaz does not believe him, and so God gives him a sign that this will be so: "Therefore the Lord himself will give you a sign. Behold, the virgin shall conceive and bear a son, and shall call his name Immanuel" (7:14).
Scholars debate to whom the text refers in its original context, with two suggestions being the wife and son of Ahaz or those of Isaiah (see Isaiah 8:1-4). However, the passage is difficult: "One of the most significant features of this verse is the mysterious, even vague and indeterminate, tone that pervades the entire passage. The reader is simply not given information regarding the identity of the maiden, or how precisely the sign functions in relation to the giving of the name Immanuel." What is known with certainty is that God gave Ahaz a sign in the form of a woman conceiving a son and naming him "Immanuel." The sign was to demonstrate that God was "with" his people, and with the line of David, and that his word would be kept, in spite of their unbelief.
"Emmanuel" in Matthew
Matthew draws from this prophecy. The prophecy served its purpose in Isaiah's day, but Matthew saw in it a fuller purpose, which was to point to the coming Messiah who would also be conceived by a virgin. In Isaiah, the prophecy of 7:14 is directed to the house of David, and its prophecy of a child to be born prepares the audience for the prophecy of 9:6-7 of a "child who is to be born 'for us,' and whose multiple and still more extravagant title marks him out not only as the Messiah of the line of David but also as 'Mighty God, Everlasting Father.'" Thus, the passages in Isaiah invite a fuller interpretation, and this is what is given in Matthew's account of the birth of Jesus.
In Isaiah, the name "Emmanuel" and its surrounding context speak of "the dawn of the promised golden age with the judgment of the wicked and the blessing of the righteous . . . . This was the ultimate sense in which God's presence was to be manifested in Israel." In Matthew, then, the name is applied to Jesus, which means that this promised blessing of God being with his people spreads to all who will believe in him in the entire world. Jesus fulfills the prophecy because he "will save his people from their sins" (1:21). The theme of "God with us" continues through Matthew until the very end, where it culminates in the Great Commission and the last verse of the book: "And behold, I am with you always, to the end of the age" (28:20).
"Emmanuel" and Christmas
The name "Emmanuel" clearly works on the prevalent biblical theme of God's presence with his people. The idea of "God with us" is the embodiment of all of God's promises to Israel and to all who will trust in him. Through sacrifice and mercy God makes a way to be with his people, whether Israel in the Old Testament or the church in the New Testament, all leading up to God's final act in Revelation 21:3: "And I heard a loud voice from the throne saying, 'Behold, the dwelling place of God is with man. He will dwell with them, and they will be his people, and God himself will be with them as their God.'"
Jesus is the ultimate fulfillment of this theme, both in his identification with humanity by becoming a man and by his death on the cross for sin. In this sense, the word "Emmanuel" truly does embody the meaning of Christmas. The birth of Jesus, the Holy One of Israel, the Messiah and Savior of all men, has made a way for God to be "with us."
 See John T. Willis, "The Meaning of Isaiah 7:14 and Its Application in Matthew 1:23," Restoration Quarterly 21 (1978): 3-4.