Ask someone who is even vaguely aware of the Bible, “What is Immanuel?” and they’ll tell you the answer is “Jesus.” But what a lot (I’d guess it is close to 99%) of religious people don’t realize is that the word “Immanuel” only appears once in the New Testament, but twice in the Old.
The first instance is Isaiah 7:14 (which Matthew quotes and applies it to Jesus). In that context, Isaiah has gone to the king of Judah, and asks him to select a sign from God so that he can know Isaiah’s prophecy would come to pass (this prophecy was that the two kings—and they are mentioned by name—who were giving Judah trouble would be defeated). The king refuses to ask for a sign, so Isaiah gives him one—again, to prove that the prophecy just given would come to pass. He says that “the virgin shall conceive, and shall bear a child, and shall call his name Immanuel…” and Isaiah adds some other details, showing that by the time this child is just a few years old (if that), these two kings would be gone.
This word Immanuel means “God with us.”
In Isaiah 8, God says that before Isaiah’s son is old enough to say “my father” or “my mother,” those same two kings would be defeated. Then in verse 8, after God shows that the Assyrian will be used to defeat the enemies of Judah, He lets them know that Judah (because of their unbelief and reliance on earthly power) would also be overtaken “up to the neck” (that is, not completely, but close. The only reason they aren’t completely overcome is because of God. At the end of the verse, God says “O Immanuel.”
So, much more than simply being a name/description applied to Jesus, the word Immanuel serves both then and now as a promise that God is there, God knows, God cares, God sees, God punishes, but God also saves.
-Bradley S. Cobb