Listen! It’s the voice of someone shouting, “Clear the way through the wilderness for the LORD! Make a straight highway through the wasteland for our God! Fill in the valleys, and level the mountains and hills. Straighten the curves, and smooth out the rough places. Then the glory of the LORD will be revealed, and all people will see it together. The LORD has spoken!” — Isaiah 40:3-5, NLT
Luke quotes from this OT prophecy in Luke Luke 3:4-6, but when he comes to the phrase “the glory of the Lord,” he writes it this way:
And then all people will see the salvation sent from God.
According to Ben Witherington, the blogging professor of New Testament at Asbury Seminary in Kentucky, Luke is using the LXX Greek translation of the Hebrew Old Testament as his source, where in this case “glory” is rendered “salvation.”
Witherington explains some of the implications of that in his post The Glory = Salvation of God — All flesh will see it together.
Here’s an excerpt:
The term salvation of course makes clear the end or aim of the revelation, and also the glory. The aim is the rescuing, saving, redemption of both Gentiles and Jews.
Here I think, in our wonderful Christmas story is as clear a revelation of the other-directed character of God, which involves God revealing, saving, and bringing glory to his people.
…The glory of God is most revealed when God indiscriminately saves people, whether they are part of his chosen people or not. The salvation ‘which all flesh will see’ reveals the real heart and character of God — which is other directed, and self-sacrificial, even to the point of giving up his only Begotten Son. In other words, God doesn’t just exhibit a covenant love to those whom he has always and already promised redemption, help healing — his Jewish people. God comes and saves those he has made no promises to, and has had no covenant relationship with at all!
Good stuff. Go read the whole thing..