The only Biblical reference in there is Isaiah, with these two lines:
42.6 “I the LORD have called thee in righteousness, and have taken hold of thy hand, and kept thee, and set thee for a covenant of the people, for a light of the nations;”
49.6 “Yea, He saith: ‘It is too light a thing that thou shouldest be My servant to raise up the tribes of Jacob, and to restore the offspring of Israel; I will also give thee for a light of the nations, that My salvation may be unto the end of the earth.’”
But 42 then continues on:
“The LORD will go forth as a mighty man, He will stir up jealousy like a man of war; He will cry, yea, He will shout aloud, He will prove Himself mighty against His enemies. I have long time held My peace, I have been still, and refrained Myself; now will I cry like a travailing woman, gasping and panting at once. I will make waste mountains and hills, and dry up all their herbs; and I will make the rivers islands, and will dry up the pools. […] They shall be turned back, greatly ashamed, that trust in graven images, that say unto molten images: ‘Ye are our gods.’”
Which is to say, “I’ll slaughter people until they stop worshiping other people than me.” While I have no complaint as to whether one does or doesn’t worship Yahweh, I wouldn’t put said worship as being equivalent to “making the world a better place”. In the context, I don’t believe that 42.6 can really be read to have the meaning that it’s given quoted out of context.
Section 49, on the other hand, I would somewhat agree with the interpretation.
“Thus saith the LORD, the Redeemer of Israel, his Holy One, to him who is despised of men, to him who is abhorred of nations, to a servant of rulers: kings shall see and arise, princes, and they shall prostrate themselves; because of the LORD that is faithful, even the Holy One of Israel, who hath chosen thee. Thus saith the LORD: In an acceptable time have I answered thee, and in a day of salvation have I helped thee; and I will preserve thee, and give thee for a covenant of the people, to raise up the land, to cause to inherit the desolate heritages; Saying to the prisoners: ‘Go forth’; to them that are in darkness: ‘Show yourselves’; they shall feed in the ways, and in all high hills shall be their pasture; They shall not hunger nor thirst, neither shall the heat nor sun smite them; for He that hath compassion on them will lead them, even by the springs of water will He guide them. […] Behold, these shall come from far; and, lo, these from the north and from the west, and these from the land of Sinim. […] For thy waste and thy desolate places and thy land that hath been destroyed–surely now shalt thou be too strait for the inhabitants, and they that swallowed thee up shall be far away. The children of thy bereavement shall yet say in thine ears: ‘The place is too strait for me; give place to me that I may dwell.’ Then shalt thou say in thy heart: ‘Who hath begotten me these, seeing I have been bereaved of my children, and am solitary, an exile, and wandering to and fro? And who hath brought up these? Behold, I was left alone; these, where were they?’ […] And I will feed them that oppress thee with their own flesh; and they shall be drunken with their own blood, as with sweet wine; and all flesh shall know that I the LORD am thy Saviour, and thy Redeemer, the Mighty One of Jacob.”
This is a call to charitable acts and I would agree, in modern day, that charity is generally seen as being equivalent to “making the world a better place”.
But a cynical eye would note that this is explicitly targeted to groups who have been attacked by other nations. E.g., if the Egyptians came in and attacked Phillistine, then the Jews would be welcoming and helpful to the Philistines in the aim of showing them Yahweh’s greatness.
But there’s no restriction on the Jews to go and attack other nations. If the Yahweh tells the Jews to go attack Philistine, then that’s an entirely different ballgame and they’re just out of luck afterwards (as slaves and slave wives). Nor is there any attempt or recommendation for dealing with the bigger nations - like Egypt or the Achaemenid Empire - and convince them to be better. They’re just written off.
The cynical reading would be less that this is an act of charity so much as it’s an endorsement to try and make pals with other small-fry nations, in the hopes of building enough strength to go up against Egypt and the other mega-powers. Which matches the final line I quoted, where Yahweh (through Isaiah) is saying that the mega-powers will be made to suffer (eventually).
Of course, as it ended up, the Jewish state went from being a vassal state of Egypt to a vassal state of the Achaemenid Empire to being a vassal state of Rome, to being destroyed. History doesn’t strongly support the image that Yahweh was portraying.
And, of course, most of the Tanakh is not Isaiah.