Gideon, Isaiah is stating that He gave the Jews the Torah and we are to use its instructions to be a light unto the nations. Those who turn to that light and follow G-d's instructions (and follow the light given by Jews) will be saved from His wrath (I will give rest).  The primary point of this chapter (remember chapters are a Christian invention) is that most non-Jews have mistreated Jews and they will be judged when the time comes (My arms will chastise  nations ). . . non-Jews who turn to G-d and Torah will also be judged, but they will be safe from His wrath (the  islands will put their hope in Me and will trust in My arm).

Artscroll's Stone Edition:
3  For HaShem will comfort Zion. . . .
4 Pay attention to Me, My people; give ear to Me, My nation; for instruction (Torah)  will come forth from Me
and My judgement will be a light for peoples, to whom I will give rest.
5 My righteousness is near; My salvation has gone forth;
My arms will chastise nations; the islands will put their hope in Me and will trust in My arm.
It says nothing about all non-Jews having their immortal souls "saved." There is no such concept in the entire Jewish bible, and most certainly not in Isaiah 51.

סופי

And everything that Sarah tells you, listen to her voice. Bereshit (Genesis) 21:12
Last Edited By: Sophiee1 Thu, 25-Aug-11 09:02:13. Edited 2 times.