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.