Question:

Why are there so many different customs regarding the time frame that sefirat haomer mourning customs apply? Why isn't there one standard for all Jews to follow?

Answer:

You ask a very astute question, one that touches at the heart of the Jewish people. Indeed there are many different customs regarding the time frame of the sefirat haomer mourning period, (click here for more about sefirat haomer mourning practices,) but your question applies to many areas of Jewish life. Let me briefly explain why the phenomenon of differing traditions and opinions is so ubiquitous in Judaism.

The Jewish nation consists of twelve (or thirteen, if you count the tribe of Levi) distinct tribes. Despite our common denominator, our individual relationship with G‑d and the way we serve Him is colored by many influences, including our tribal origins. The various customs set down in halacha (Jewish law) correlate to this plurality.

In plain words, we do not come out of the same cookie-cutter. The different customs reflect the multiplicity of ways of relating to G‑d that characterizes our people.

The Talmud1 addresses your question like this:

A man may say: "How shall I learn Torah in these circumstances [given the many different opinions]?" Therefore it is written:2 "All of them are given from one Shepherd." One G‑d gave them and one leader [Moses] uttered them from the mouth of the L-rd of all creation, blessed be He, as it is written: "And G‑d spoke all these words."3

Once you clarify your own particular customs with the guidance of your rabbi, the path you need to follow will no longer baffle you.

Please accept my wishes for a meaningful and inspiring sefirah!

Rabbi Eliezer Danzinger for Chabad.org