Unbelievers typically contend that Matthew quoted Isa 7:14 out of context. Actually, it’s unbelievers who quote Isa 7:14 out of context.
The use of Isa.7:14 in Matt.1 is best understood by J.A. Motyer (“Context and Content in the Interpretation of Isaiah 7:14,”Tyndale Bulletin 21 : 118-25). Signs in the OT may function as a present persuader (e.g., Exod 4:8-9) or as “future confirmation” (e.g., Exod 3:12). Isaiah 7:14 falls in the latter case because Immanuel’s birth comes too late to be a “present persuader.” The “sign” (v.11) points primarily to threat and foreboding. Ahaz has rejected the Lord’s gracious offer (vv.10-12), and Isaiah responds in wrath (v.13). The “curds and honey” Immanuel will eat (v.15) represent the only food left in the land on the day of wrath (vv.18-22). Even the promise of Ephraim’s destruction (v.8) must be understood to embrace a warning (v.9b; Motyer, “Isaiah 7:14,” pp. 121-22). Isaiah sees a threat, not simply to Ahaz, but to the “house of David” (vv.2, 13) caught up in faithlessness. To this faithless house Isaiah utters his prophecy. Therefore Immanuel’s birth follows the coming events (it is a “future confirmation”) and will take place when the Davidic dynasty has lost the throne.
Motyer shows the close parallels between the prophetic word to Judah (7:1-9:7) and the prophetic word to Ephraim (9:8-11:16). To both there come the moment of decision as the Lord’s word threatens wrath (7:1-17; 9:8-10:4), the time of judgment mediated by the Assyrian invasion (7:18-8:8; 10:5-15), the destruction of God’s foes but the salvation of a remnant (8:9-22; 10:16-34), and the promise of a glorious hope as the Davidic monarch reigns and brings prosperity to his people (9:1-7; 11:1-16). The twofold structure argues for the cohesive unity between the prophecy of Judah and that to Ephraim. If this is correct, Isaiah 7:1-9:7 must be read as a unit—i.e., 7:14 must not be treated in isolation. The promised Immanuel (7:14) will possess the land (8:8), thwart all opponents (8:10), appear in Galilee of the Gentiles (9:1) as a great light to those in the land of the shadow of death (9:2). He is the Child and Son called “Wonderful Counselor, Mighty God, Everlasting Father, Prince of Peace” in 9:6, whose government and peace will never end as he reigns on David’s throne forever (9:7).
Much of Motyer’s work is confirmed by a recent article by Joseph Jensen (“The Age of Immanuel,” CBQ 41 : 220-39; he does not refer to Motyer), who extends the plausibility of this structure by showing that Isaiah 7:15 should be taken in a final sense; i.e., Immanuel will eat the bread of affliction in order to learn (unlike Ahaz!) the lesson of obedience. There is no reference to “age of discretion.” Further, Jensen believes that 7:16-25 points to Immanuel’s coming only after the destruction of the land (6:9-13 suggests the destruction extends to Judah as well as to Israel); that Immanuel and Maher-Shalal-Hash-Baz, Isaiah’s son (8:1), are not the same; and that only Isaiah’s son sets a time limit relevant to Ahaz.
The foregoing discussion was unavoidable. For if Motyer’s view fairly represents Isaiah’s thought, and if Matthew understood him in this way, then much light is shed on the first Gospel. The Immanuel figure of Isaiah 7:14 is a messianic figure, a point Matthew has rightly grasped. Moreover this interpretation turns on an understanding of the place of the Exile in Isaiah 6-12, and Matthew has divided up his genealogy (1:11-12, 17) precisely in order to draw attention to the Exile. In 2:17-18 the theme of the Exile returns. A little later, as Jesus begins his ministry (4:12-16), Matthew quotes Isaiah 9:1-2, which, if the interpretation adopted here is correct, properly belongs to the Immanuel prophecies of Isaiah 7:14, 9:6. Small wonder that after such comments by Matthew, Jesus’ next words announced the kingdom (4:17; cf. Isa 9:7). Isaiah’s reference to Immanuel’s affliction for the sake of learning obedience (cf. on Isa 7:15 above) anticipates Jesus’ humiliation, suffering, and obedient sonship, a recurring theme in this Gospel.
This interpretation also partially explains Matthew’s interest in the Davidic lineage; and it strengthens a strong interpretation of “Immanuel.” Most scholars (e.g., Bonnard) suppose that this name in Isaiah reflects a hope that God would make himself present with his people (“Immanuel” derives from immanuel , “God with us”); and they apply the name to Jesus in a similar way, to mean that God is with us, and for us, because of Jesus. But if Immanuel in Isaiah is a messianic figure whose titles include “Mighty God,” there is reason to think that “Immanuel” refers to Jesus himself, that he is “God with us.” Matthew’s use of the preposition “with” at the end of 1:23 favors this (cf. Fenton, “Matthew 1:20-23,” p. 81). Though “Immanuel” is not a name in the sense that “Jesus” is Messiah’s name (1:21), in the OT Solomon was named “Jedidiah” (“Beloved of Yahweh,” 2Sam 12:25), even though he apparently was not called that. Similarly Immanuel is a “name” in the sense of title or description.
No greater blessing can be conceived than for God to dwell with his people (Isa 60:18-20); Ezek 48:35; Rev 21:23). Jesus is the one called “God with us”: the designation evokes John 1:14, 18. As if that were not enough, Jesus promises just before his ascension to be with us to the end of the age (28:20; cf. also 18:20), when he will return to share his messianic banquet with his people (25:10).
If “Immanuel” is rightly interpreted in this sense, then the question must be raised whether “Jesus” (1:21) should receive the same treatment. Does “Jesus” (“Yahweh saves”) mean Mary’s Son merely brings Yahweh’s salvation, or is he himself in some sense the Yahweh who saves? If “Immanuel” entails the higher christology, it is not implausible that Matthew sees the same in “Jesus.” The least we can say is that Matthew does not hesitate to apply OT passages descriptive of Yahweh directly to Jesus (cf. on 3:3).
Matthew’s quotation of Isaiah 7:14 is very close to the LXX; but he changes “you will call” to “they will call.” This may reflect a rendering of the original Hebrew, if 1QIsaa is pointed appropriately (cf. Gundry, Use of OT , p. 90). But there is more here: The people whose sins Jesus forgives (1:21) are the ones who will gladly call him “God with us” (cf. Frankemolle, pp. 17-19).