What’s perhaps most monumental about reciting “Sh’ma Yisroel” is that each time we do, *we bring the entire universe that much closer to perfection*. For as we learned earlier on (1:5:4 and 2:8:2), everything we do here on earth affects the entire universe (both the earthly and the celestial realms). Accordingly, when we reiterate these fundamental truths of the cosmos we bolster all of creation in the process and grant it more G-dliness.
We also authorize the forces of goodness, abundance, and peace to express themselves; and stymie the forces of evil, privation, and conflict along the way. Those who *deny* those things, on the other hand, and reject G-d’s sovereignty withhold all the good. And that’s rooted in the following two basic principles of metaphysics.
First, that all sorts of goodness and abundance manifests itself in the universe when G-d exhibits His sovereignty in the universe — which is to say, when we sense for ourselves that He alone rules. Fresh and rich new instances of holiness, pure Illumination, and goodness pour forth, while the forces of evil are subjugated and not allowed to undermine any of that. And secondly, that the forces of evil become prolific and begin to prevail when G-d’s sovereignty is hidden; and all misfortune, havoc, sorrow, and other instances of wrong hold sway.
So, what are we to do to encourage the good and deter the evil, as well as bring the universe nearer yet to perfection (as we said at the beginning)? We do that by affirming our belief in G-d’s sovereignty day after day by reciting “Sh’ma Yisroel” wholeheartedly and in full faith.
And based on the mystical principle that “every spur from below evokes a (corresponding) spur from Above”, when we recite it in that spirit, G-d reciprocates by manifesting His sovereignty in fact, and He furthers universal perfection. But understand that the ultimate universal perfection we’re speaking of — which has always been G-d’s intention — will come about in the course of the myriad everyday events we ourselves engage in that are all ultimately meant to bring it about (including, but not restricted to our reciting “Sh’ma Yisroel”).
All this serves a single purpose: to demonstrate the fact that it’s our input in concert with G-d’s great goodness that will rectify the world — it couldn’t happen otherwise. Indeed, every sequence of events will eventually result in that ultimate perfection. The other point to be made is that when we contribute to the perfection of everything else, we perfect ourselves in the process and draw as close to G-d as is possible, as G-d had likewise planned (see 1:2:2).