An engineer designs machines consisting of many parts, some more important than others. Although some parts seem to the layman to have no function at all, the engineer understands how each one is necessary for the machine to function. Because he lacks the engineer’s knowledge and expertise, a layman may mistakenly assume that the machine can still operate if a screw is taken away or added.

This metaphor can be applied to the existence of the world and the fulfillment of the mitzvos the 613 Biblical and seven Rabbinical precepts through which a person can attach himself to G‑d. If one violates the injunction, “Do not add to or subtract from the mitzvos,”1 although the addition or deletion may seem insignificant to him, the mitzvah that he is lacking (or has altered) will diminish his attachment to G‑d.

In the same way that every part of a machine has a distinct yet integral function, G‑d provided each individual with a specific task his personal sphere of influence in perfecting the world. All of the individual pieces are part of His master plan of Creation.

Sichos Kodesh of the Rebbe, Acharon Shel Pesach, 5714