What events changed Judaism from priest-led to rabbi-led?

Answer 1

The destruction of the Second Temple was a major event that changed the practice of Judaism.

Answer 2

Judaism centers around Torah-observance. This has never changed. The Torah contains many hundreds of commands, hundreds of which are applicable today too. When offering sacrifices was possible, they were offered; and when the Temple was destroyed, those particular commands of the Torah were suspended. It's like a man who lost his arms: he doesn't put tefillin on, but his Judaism hasn't changed.

• To answer the question:
  

While the Torah, its commands and the principles and beliefs of Judaism remain unchanged, Judaism has evolved as circumstances have necessitated.
1) After the end of prophecy (some 2350 years ago), the Hebrew Bible was sealed by a special Sanhedrin (Rabbinical court). It was the same Sanhedrin which placed our prayers in their permanent form (Talmud, Berakhot 33a).
2) Purim and Hanukkah were instituted after the relevant events.
3) Certain fasts were instituted in connection with the Destruction of the Temple.
4) After the Destruction, the laws of sacrifices were suspended.
5) When circumstances made it impossible, the New Moon was no longer proclaimed by testimony; rather, the fixed calendar was instituted (around 360 CE).
6) The Talmud was put in writing (around 500 CE) when it became too hard to be learned by heart.
7) There are seven formal Rabbinical commands. These are:
Saying the blessings over food (and on various occasions)
Washing one's hands before eating bread
Lighting the Hanukkah-menorah
The Eruv
Saying the Hallel prayer on certain occasions
Lighting the Sabbath candles
Reading the Megillat Esther on Purim.
In addition, there are many Rabbinical decrees, mostly from the Men of the Great Assembly (4th century BCE), as well as later enactments.
The purpose of every one of these is to provide a "fence around the Torah," meaning to shore up something that can benefit from strengthening. An example: not handling electric appliances on the Sabbath, even if they are not connected to any electric socket.

Answer 2

The answer you're looking for is "The destruction of the Jewish Temple." However, your question seems to be based on a misconception. Judaism has never been "led by priests." It has always had both kohanim ("priests") and Rabbis, from Moses onward. The two had different areas of jurisdiction, with the Rabbis having final say in matters of Jewish law, and the kohanim running the day-to-day functioning of the Holy Temple. After the Destruction, the kohanim lost some of their function, but the Rabbis became no different than they had already been. The Elders of Moses' time and later (Exodus 4:29, 17:6; Numbers ch.11, Deuteronomy 31:9, Joshua 20:4, Judges 11:5, 1 Samuel 4:3, 2 Samuel 3:17, 1 Kings 8:1, etc.) were the same body of Torah-sages that were later called the Sanhedrin and are now called Rabbis.

Answer 3

The answer you're looking for is "The destruction of the Jewish Temple." However, your question seems to be based on a misconception. Judaism has never been "led by priests." It has always had both kohanim ("priests") and Rabbis, from Moses onward. The two had different areas of jurisdiction, with the Rabbis having final say in matters of Jewish law, and the kohanim running the day-to-day functioning of the Holy Temple. After the Destruction, the kohanim lost some of their function, but the Rabbis became no different than they had already been. The Elders of Moses' time and later (Exodus 4:29, 17:6; Numbers ch.11, Deuteronomy 31:9, Joshua 20:4, Judges 11:5, 1 Samuel 4:3, 2 Samuel 3:17, 1 Kings 8:1, etc.) were the same body of Torah-sages that were later called the Sanhedrin and are now called Rabbis. See also the Related Links.

Link: How has Judaism changed?

Link: What were the different types of authority in ancient Israel?

Answer 4

The Torah and its 613 commands do not change. The only things that have changed are some Jewish customs; plus the addition of some Rabbinical decrees (such as hand-washing) which are all intended to safeguard the mitzvoth (commands) themselves.

Answer 5

While the Torah, its commands and the principles and beliefs of Judaism remain unchanged, Judaism has evolved as circumstances have necessitated.
For one example, after the end of prophecy the canon of the Tanakh was sealed by a special Sanhedrin (Rabbinical court). It was the same Sanhedrin which placed our prayers in their permanent form.

See also the Related Links.

Link: Was Judaism altered after the destruction of the Temple?

Link: Jewish history timeline