So I thought it might be nice to write a little bit about what people who aren't Jewish have to look forward to from a life lived right & how to get there.
In Rav Dessler's Strive for Truth!, Volume 2, Part 3: A Chance for the Nations, he writes that in the future, Hashem will test the nations with the mitzvah of sukkah.
Many insights into this Gemara exist, but Rav Dessler states it's because whatever degree of teshuvah (repentance) a non-Jew achieves needs a sukkah to preserve that teshuvah.
(In other words, the teshuvah isn't for nothing; Hashem will preserve it with a sukkah.)
Rav Dessler also states that the other nations will also eventually receive enlightenment from Hashem. After all, he explains, the world isn't set right until the entirety of Creation sees the truth without exception.
In Volume I, Part 2: The Individual & Society, Rav Dessler declares the non-Jewish purpose as building a world suitable for assisting the minority "actively engaged in revealing Hashem's Glory."
In other words, non-Jews who assist Jews in fulfilling their purpose greatly benefit the world & earn reward for this.
Rav Dessler notes that non-Jews who help Jews in this way both conscientiously & with the proper intentions earn the title chassidei umot ha'olam—devoted ones of the nations of the world.
These non-Jews receive a portion in the World to Come.
Why?
Rav Dessler explains that because they freely choose "to help the process of the revelation of Hashem's Glory," they deserve Heavenly reward.
Likewise, in the 1730 Me'am Lo'ez commentary on Beresheit/Genesis 1:31, Rav Yaakov Culi mentions a chamber for righteous gentiles that contains several entrances for these souls to enter (page 197-198):
These are the ones who behave decently toward the Jews and do them no harm.
They are therefore worthy of rest & repose after death.
Needless to say, none of this is physical despite the physical terms used. It contains spiritual good unfathomable in our 3-dimensional world.
There's also Rav Avigdor Miller on the 2 Torahs for the Gentiles:
Of course it’s not that easy – you have to be a chossid [devotee] in the sheva mitzvos Bnei Noach [7 laws of the children of Noah]; you have to be devoted to it, but it’s possible to get Olam Habah [the World to Come]; no question about it.
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And so to sum up – the gentiles have available to them two kinds of Torah.
One is the Torah which we call the Noachide Laws, the sheva mitzvos Bnei Noach.
If they are interested, they should come to us and we’ll tell them what those laws are.
If they don’t want to hear them and they want to abide by the laws of their common sense conscience, it’s also something – it’s not as good, but it’s something – and it can help people live a more or less balanced and happy existence in this world.
Ultimately, the non-Jewish purpose assists the Jewish purpose.
Again, it's not about Jews, per se.
For example, if a non-Jew wishes to assist a secular Leftist Jew in the anti-God path, that's really bad and NOT considered helpful.
It's about revealing Hashem's Glory in the world—which is the Jewish role in the world—therefore, this means doing so as defined according to Torah.
And the non-Jew can definitely assist with that.
Being a "clean up my own backyard first" type of person, I don't know much practically about the role or halacha [law] for non-Jews, but I hope the above helps.