They’re furry. They’re yellow. They make adorable little chirping sounds. Baby chicks are the most perfect little things, except for one thing: They don’t yet fly. They’re just not mature enough.

When a mitzvah is performed in its entirety but is lacking motivation and feeling, it is compared to a chick that cannot fly. It may fulfill all the requirements, but it cannot soar and unite with G‑d as it could when it is permeated with emotion, with kavana.

The two emotions—love and fear—are like wings that lift the mitzvah to reach its fullest potential. Just as a kosher bird that is missing its wings is still technically “kosher” (but sorely missing a key component of its being a “bird”), a mitzvah done without motivation is technically “kosher” and still a mitzvah, yet missing an essential ingredient of being one.

Why is kavana so crucial to a mitzvah? Because a mitzvah itself is a very physical activity, done with very mundane items. Physicality operates under an illusion that it has its own existence, and G‑d is not readily apparent on planet Earth. Since mitzvahs are done with physical objects that by their very nature disguise G‑dliness, in order for the mitzvah to pierce through the illusion and rise heavenward, it needs a spiritual boost. The spiritual nature—and the emotional and mental effort of kavana—serves as the spiritual engine that propels a mitzvah to be able to rise and unite with G‑d.

This doesn’t imply that one should pursue spiritual passion as an end in itself. That would be similar to a thirsty person who looks longingly at a cool glass of water without taking a sip to quench his thirst. The whole point of spirituality is to arouse an intense love and longing for G‑d, which can only be quenched by actually drinking His Torah and doing His mitzvot.

When you have the “body” of the mitzvah combined with its “soul,” the mitzvah has reached maturity.

Tanya Bit: A “mature” mitzvah is one that is fulfilled with passion, allowing it to soar heavenward and unite with G‑d.

(Inspired from Chapter 40 of Tanya)