Question:

Why is it so important that we learn about mitzvot that have no bearing on our life any more; e.g. all the provisions for sacrificing animals—although we have not sacrificed animals since the destruction of the Temple?

Answer:

That is an excellent question. What is the purpose of studying something which has no practical application? Should I pursue an area of medicine that studies a disease that no longer exists? Not if my goal is to treat today's patients. Why doesn't the same logic apply to the Torah?

Here are a few thoughts on this topic:

a) The Torah in its entirety is G‑d's wisdom. It is a condensation of G‑d's understanding applied to words on paper. By studying any aspect of Torah, practical or not, one gains an insight into G‑d's wisdom. Undoubtedly, such insight provides messages and guidance for all areas of life.

b) According to chassidic teachings, Torah study's ultimate benefit isn't the practical knowledge gained, but the unity it creates between G‑d and the one studying the text. See A Marriage of Minds for more on this subject.

c) By studying those laws that were once applicable and are not so any more, due to the fact that we do not have a Temple in Jerusalem, we are hastening the time that these laws will once again become relevant with the coming of Moshiach, our righteous redeemer. We are demonstrating to G‑d that these laws are so precious to us, that although we cannot apply them we continue to study them. G‑d will surely respond by making this era come speedily in our days.

d) Through studying about these mitzvot, it is considered as if we actually have fulfilled them. For more on this, see How does one find atonement in the absence of sacrifices?

e) The Torah is multi-layered. While on its simplest level it teaches us practical rules, each mitzvah has profound meaning on a spiritual level, too. Using sacrifices as an example: The sacrifice of a physical animal in order to attain atonement is but a reflection of a spiritual truth—the sacrifice that must take place within the mind and heart of the person who strayed and wants to regain G‑d's favor. (For more on this, see Are You Really Planning to Bring Back those Animal Sacrifices?) When we study the particulars and details of the mitzvot it behooves us to pause and try to understand the deeper message, the mitzvah's deeper layers.

All the best,

Rabbi Shmuel Kogan,
Chabad.org