“Therefore the Lord himself will give you a sign. Behold, the virgin shall conceive and bear a son, and shall call his name Immanuel.”
A naturally conceived-and-born descendant of Adam cannot save God’s people from their sin (Ps. 49:7–9). Being part of the sinful lineage that descends from Adam via ordinary procreation, he is enslaved to sin and guilty before God from conception, just like us. Yet we still need some kind of creaturely mediation to be saved — only a human being can atone for the sin of other human beings. This Savior must be truly human, possessing all that is essential to mankind. A human Savior who is free from original sin and never commits sin Himself remains truly human because sin is not inherent to human identity; rather, sin is a later addition that “de-humanizes” us. Adam was truly human before he sinned (Gen. 1:26–27).
Clearly, supernatural intervention in the post-fall world is needed to provide a sinless Mediator who can atone for our sin. The Lord told His old covenant people to expect this miracle, and today’s passage is a key prophecy of the Redeemer’s arrival. Isaiah first delivered this divine word to King Ahaz of Judah during a great upheaval. Assyria was on the march, conquering every nation in its path. Syria and Israel formed an alliance to stand up to this bully, and they wanted Judah on their side. Ahaz initially refused, so Rezin of Syria and Pekah of Israel pledged to conquer Judah and install a puppet king who would join them against Assyria (Isa. 7:1–6).
Understandably, Ahaz was tempted to give in to Israel and Syria in order to keep his throne. Promising to preserve Judah if Ahaz would trust God and not human kings, the Lord told Ahaz to ask for a sign to confirm His promise (vv. 7–11). Ahaz’s refusal of this offer did not show true piety (v. 12). As J. Alec Motyer writes in The Prophecy of Isaiah, “To refuse a proffered sign is proof that one does not want to believe” (p. 83). God gave the sign, which may have been fulfilled initially in the normal birth of a child to the royal court, but it pointed to Ahaz’s end (vv. 13–17).
Jesus is the ultimate fulfillment of Isaiah’s prophecy because He was conceived by the Holy Spirit and born of a true virgin (Matt. 1:22–23; Luke 1:26–38). He is the Lord’s supernatural intervention, the sinless Mediator who is truly human and truly God. Moreover, He signifies a destruction greater than Ahaz’s end, for all who reject the Lord’s promises in Him will feel His eternal wrath (Rev. 20:11–15).
Coram Deo
Other religions may have some idea of divine intervention in that God sendsa message through a seer or “prophet,” but no other religion has as radicala view of divine intervention as orthodox Christianity. The Christian faith tellsus that God Himself entered human history in the person of Christ Jesus andrepresented His people in order to save us from sin. We should be profoundlygrateful for this act and therefore live in obedience to Him.