The sign of Immanuel (God with us) is given to King Ahaz. As the kings of Israel and Syria are conspiring to attack Judah, Isaiah ("God is salvation") and his son, Shear-jashub ("a remnant shall return") are called to go to King Ahaz in Jerusalem (Is. 7:3).
A country is divided and has been for some time - Israel and Judah, one faithful (Judah) and one apostate (Israel). Israel has aligned itself against the remnant of God's people and the man named God is salvatioin is sent with his son named "a remnant shall return" to ensure that the next sign of God's favor "God with us" is received. Ahaz has refused to seek a sign from God, but in comes in spite of his refusal. "Emmanuel" - God's promise of hope, of assurance, of steadfast presence with His people, in spite of the circumstances.
Assyria, Babylon, Egypt, Israel, Syria...each in their own time and way serve to threaten God's remnant people...a constant source of conflict for God's children, those who hold out faithfulness, who stand firm...And Judah, a part of what was once a great and united kingdom, will eventually be taken into captivity.
This prophecy, which to our great disservice, we seem to only lift up at Christmas, is timeless. It is once and forever true, the definitive sign of God's presence with us. Though the enemies of God may have their way, for a time and a season, God is always with His people. He will never be without a remnant.
In this, and any trying time, as the enemies of God conspire, approach, attack, and even seem victorious, we need to remember and to reflect on this prophecy, so that we might have the confidence of God's promise of Immanuel. That is the eternal gift of Christmas, not a season, not a day, but an eternal gift of hope. God IS with us. Amen!