What is the purpose of gemilus chassadim, the acts of kindness?
There is a ma'amor by the Rebbe that says that there are three levels of avoida:
1. The lowest level is tzedaka: it brings about the "reparation" of the lower worlds
2. The middle level is mitzvos and Torah: it brings about the increase in the keilim of Atzilus
3. The highest level is gemilus chassadim: it connects a person to the Kesser (the siman of that is that gemilus chassadim transcend time; when you give someone a loan, the act of the loan keeps existing even beyond the moment of the giving)
One could ask: the bottom two levels benefit both the person and the purpose with which Hashem created the world (so that people bring Him into the world). But what is the point of connecting to Kesser which is above Seider Hishtalshelus? How can Hashem or a Yid care about that?
The point is that the relationship itself is the purpose.
This is reflected how one does kindness to another person not because of some calculation, but because the act itself is its own purpose. When you give yourself over to the mashpia, what do you get? The hashpo'oh? No: you get the mashpia himself.
I want to add personally that this is also reminiscent of the idea of metziuso m'atzmuso: the existence of something is from its own essence. This is only true about Hashem. But it also feels true about this world, because this world shares connection with Atzmus. Which is why only through the physical mitzvos in the physical world can one get to Eibeshter (in this sense, Judaism differs from Christianity in that the matter is higher than the form; the act is higher than the purpose and is a purpose in itself).
So, what is the point of morality? Modern moral relativists either reject morality at all or define it in some relative term: I should act morally because people will be nice to me, because it will be better for my personal virtues, because I happen to like it, because it's aesthetically pleasing to me.
That's narishkeit. We all know that people ought not to kill each other because killing is wrong. The fact that killing hurts the victim's family, the fact that it destabilizes the society, the fact that it affects the killer himself — all of that is true. But even if all that were not true (the killer has no relatives, he felt no pain, the murder happens on a deserted island, and the killer is a psychopath beyond repair), we still know that the fact of killing itself was evil. Everyone intuitively knows that, unless he is a sociopath (in which case we say that he cannot "see" morality like a blind person cannot see light).
So, we don't keep morality because it produces some result. Keeping it is the purpose itself. Metziuso m'atzmuso. When we do that, we connect to Atzmus of Hashem (who has endowed us with a moral compass and a sense of imperative in our everyday lives, besides Halacha): not for some purpose, but just for the sake of connecting to Hashem, in and of itself.