Let’s start to explore the details of reward and punishment. In general, the system is rooted in an originator, G-d Almighty, and ourselves as recipients. We will dwell on G-d’s role for some time (first in general and then more specifically), then touch on our own .
G-d interacts with us in infinite numbers of ways, but in general He does so lovingly, firmly, or by a combination of the two. For even when He’s exacting in His expectations of us it’s still-and-all done with loving intentions, as we’re told that “the L-rd your G-d disciplines you as a man disciplines his son” (Deuteronomy 8:5). That’s to say that G-d does indeed chastise us at times, but with our own well-being in mind, and with the insight and deep love one would expect of a caring, worldly-wise parent — certainly without malice or vengeance.
That sort of chastisement is meant to blunt any harm that would come our way had we not been forewarned and forestalled. And it’s always rooted in the recognition of what’s ultimately good for us and of our ultimate aim in life .
G-d also knows of course when we simply can’t shoulder His expectations, and so He oftentimes withholds His chastisements in great mercy and sympathy.
So we’d need to explore the full gamut of all that.
 For Kabbalistic references see Klallim Rishonim 20-21, R’ Goldblatt’s note 9, and R’ Shriki’s notes 99-100.
 Some are troubled in our day by the whole notion of G-d chastising us for our own good and of His always having our well-being in mind, given modern circumstances. There are no easy answers for that, but just know that a major component of Ramchal’s thinking is that everything will prove to have been for the ultimate good in the end even if we don’t understand at the time. For a full treatment of Ramchal’s discussions of this in nearly all of his works (Da’at Tevunot included), see R’ Yoseph Avivi’s Zohar Ramchal pp. 89-294.
We’d also add this statement from Bachya Ibn Pakudah’s The Duties of the Heart, “If you would only realize … that your Creator … knows better than you ever could what is good for you and what is not, you would accept each favor bestowed and would have more and more heart-felt gratitude” (3:6).
Rabbi Yaakov Feldman has translated and commented upon “The Gates of Repentance”, “The Path of the Just”, and “The Duties of the Heart” (Jason Aronson Publishers). His works are available in bookstores and in various locations on the Web.