Learning at the uppermost levels necessitates regimen. Going to law school requires prerequisites; there are mandatory courses to take prior to med school and even pre-reqs for nursing school.

College courses have prerequisites because before taking a high-level class, students need to be prepared. This ensures that students have a foundation of knowledge and experience in order to advance to more complex concepts.

Torah and mitzvot have some basic prerequisites as well. There is typically a hierarchy of emotions when it comes to fulfilling Torah and mitzvot, and you can't skip levels because one builds on the other.

1. ‘Lower-level’ reverence and awe of G‑d

The sages say, “If there is no reverence, there is no wisdom.” In order to access the wisdom of Torah and mitzvot, there is a “prereq”; you must have a basic level of reverence for G‑d.1 It is an easier, lower level of fear and reverence, but nevertheless crucial in order to serve G‑d properly. It is when you feel so in awe of G‑d that you wouldn’t dare disobey Him. It is the feeling that emerges from meditating on G‑d’s presence in both the physical and spiritual worlds, followed by actually performing the mitzvot.

2. ‘Lower-level’ love of G‑d

Fulfilling Torah and mitzvot is a prerequisite; only then can you climb the ladder and experience love of G‑d. This level is called Ahavas olam, or “worldly love.” It is a love acquired from transferring your love of material pleasures to a love of spiritual pleasures. Naturally, you are wired to love physical pleasures. But rather than loving ice-cream, you can train yourself to love the Creator of ice-cream by recognizing that compared to G‑d, something like ice-cream has no value. Since this food is dependent on G‑d for its existence, it is transient, as opposed to G‑d, who is real and everlasting. Who or what is more deserving of your love? Once you comprehend that G‑d is the true source of all physical pleasures—and therefore much greater than them—you can shift your love from the worldly to the infinite.

3. ‘Higher-level’ reverence and awe of G‑d

The sages also say, “If there is no wisdom, there is no reverence.” Observing Torah and mitzvot is a prerequisite to the higher level of reverence, which isn’t about G‑d’s powers and abilities, but about G‑d Himself.

A lower level reverence can be compared to the fear of a king, which is essentially a fear based on externalities, the king’s might and power. The more powerful the king, the greater is the fear. On the other hand, this higher level is similar to the feeling of embarrassment and sense of abnegation when in the presence of true greatness. At this level, you lose your sense of self completely. You are not just in awe of G‑d; you suspend your ego entirely. It’s not about abstaining from acting out on your desires for the sake of G‑d; you simply don't feel your desires! You stop feeling like a separate identity from G‑d, and instead feel like you are truly one with Him.

4. ‘Higher-level’ love of G‑d

The higher level of reverence is a prereq for an intense love of G‑d, where a person does not allow physicality to hide G‑d from him. This level is known as Ahava rabbah, a “great love.” This type of passionate love of G‑d is a foretaste of the world to come.

However, this intense love is not accessible to all. It is granted as a gift from G‑d to a select few, who have succeeded in “climbing the ranks” of the previous levels, reaching an emotional maturity and perfecting their service of G‑d.

For the rest of us, the main thing is to keep climbing.

Tanya Bit: Awe of G‑d is a prereq to serving G‑d; however, it is just the foundation.

(Inspired from Chapter 43 of Tanya)