Our having souls and bodies doesn't just come down to having two good reasons for living a good and righteous life. In point of fact, each is meant to explain things about G-d and the functions of the world at large, and to act as a paradigm of certain cosmic phenomena .
And so the body isn't only a product of G-d's hiding His presence, the body reveals things about that hiddenness; and the soul isn't only a product of G-d's revealing His presence, it also reveals things about that revelation. After all, we're told that man was created in G-d's 'image' and 'likeness' (Genesis 1:26), which means to say that our makeup reveals things about G-d's ways in this world .
Ramchal points to the fact that while our body parts each play out their assigned roles in due course, in that the eye sees, the ear hears, and the nose smells, still and all, not one of those organs can do what the others do -- each is unique and distinct. The soul on the other hand is a single sheer, all-encompassing entity and hasn.t any component parts with distinct roles. Each of those details speaks to the nature of G-d's hiddenness and revelation.
For G-d's being is a single sheer, all-encompassing entity -- like the soul. And the more revealed His presence is to us, the clearer that fact becomes. Yet G-d uses all kinds of means of interacting with us, which, like our assorted body parts, are each unique and distinct. And we especially catch sight of them when G-d's presence is hidden from us and we forget His own sheer, all-encompassing role in everything.
Ramchal's contention is that G-d wanted us to catch the difference between the two effects -- singularity and plurality -- in our own beings and to draw conclusions from them about G-d's presence.
Ramchal reveals that the very fact that our eyes see illustrates the idea that G-d 'sees' -- He oversees and notes everything in this world ; the fact that our ears hear alludes to the notion that G-d 'hears' -- He listens to and notes our prayers; and the fact that our mouths speak alludes to the detail that G-d 'speaks' -- communes and interacts with, and responds to us. And he offers that we're comprised of two complementary right and left halves with matching ears, arms, legs, inner organs, etc., to exemplify the fact G-d interacts with us both powerfully and lovingly  or the reverse .
As Ramchal terms the analogy, 'just as the parts of the body are separate and differentiated by their functions, mankind's experiences (are differentiated) by G-d's hiddenness', which is to say, just as wesee separate parts of our body doing disconnected things and forget that all those actions emanate from a single soul (our own), we likewise forget that while many things contribute to the world nonetheless everything emanates from G-d (the world's 'soul'), because His presence is so hidden from us.
Indeed, our having a soul is meant to remind us of G-d's all-encompassing nature, which is itself a 'unified whole', as Ramchal puts it. G-d doesn't function piecemeal. And we're to infer from that fact the idea that our soul's mission is to purify (i.e., unify and make whole) our body in the end, which is illustrative of G-d's presence.
This perspective, by the way, hoists the whole notion of man having 'created G-d' in his own image as come claim on its own petard ! For while some claim that we seem to have created a transcendent being who is based on our own capacities, Ramchal's asserts that the very opposite is true! G-d created us in His image to be sure, and for a high purpose: to illustrate things about Him and to draw us closer to Him.
 R' Shriki directs us to similar and illustrative remarks Ramchal made in Klallim Rishonim 23 and Klach Pitchei Chochma 4, 9. He also points us to Klallim Rishonim 6, and Peirush lMa'amar Vayehe Miketz (found in Ginzei Ramchal p. 292) for the Kabbalistic implications of this chapter. R' Goldblatt also draws upon Klallim Rishonim 6 in his note 24 but offers other Kabbalistic insights in notes 11 and 22.
 The theologically perplexing idea of mortal man's having been created in transcendent and non-material G-d's 'image' and 'likeness' was discussed at great length in Jewish thought. Like many others did in his wake, Rabbi Akiva presented it as a statement of man's great spiritual potential (Pirkei Avot 3:15). But see the various classical commentaries to that verse (as well as Meshech Chochma there, Ramban at 2:7, and R' Sh. R. Hirsch at 1:27), as well as Kuzari 4:3; Rambam's Moreh Nevuchim 1:1, Hilchot Yesodei HaTorah 4:8, and Hilchot Teshuvah 10:6; R. Y'I. Chaver's Siach Yitzchak, Likkutim, p. 286; Nephesh HaChaim 1:3; Michtav M'Eliyahu 1, p. 32; Maharal M'Prague's Derech haChaim 3:14; and Zohar Chadash 1:28b, etc.
 Ramchal adds that our having eyes also comes to illustrate the Talmudic statement that 'A judge can (and must only) depend on what's before of his eyes' (Sanhedrin 6b). But that seems curious in that it speaks to the limitations of our eyesight, whereas G-d's eyes see each and every thing. Ramchal must be alluding to the simple fact that we canindeed see, and that were it not for that we couldn't make judgments about anything.
 As represented by the right hand and arm, as in 'it was not their arms which kept them safe; but (rather,) Your right hand' (Psalm 44:3), 'Your (right) hand is strong, Your right hand is (also) exalted' (Psalm 89:13), and 'His left arm lay under my head and His right arm embraces me' (Song of Songs 2:6). Kabbalists often speak of G-d's 'right side' representing His loving kindness and His 'left side' representing His aversion. See 'Elijah's Prayer' in the second introduction to Tikkunei Zohar, Zohar 1:109b etc.
 The last verse cited above -- 'His left arm lay under my head and His right arm embraces me' also suggests that while His right arm embraces me, His left arm only lies under my head and doesn't embrace me.
 It was Mark Twain who said quite sardonically that 'G-d created man in His image, and man has returned the favor'.
Rabbi Yaakov Feldman has translated and commented upon "The Gates of Repentance", "The Path of the Just", and "The Duties of the Heart" (JasonAronson Publishers). His works are available in bookstores and in variouslocations on the Web.