How did Judaism spread to Israel?

Even those who claim that the Judaism evolved and developed are in agreement that Judaism had developed for the most part prior to creation of the Diaspora and the Spreading of the Religion. The real changes occurred after the Destruction of Temple in Jerusalem the first time in 586 BCE and were solidified after the Second Temple was destroyed in 70 CE. By the mid 100s CE, Judaism was defined more or less by the laws and ideals it currently has. Judaism spread geographically within the next few centuries as Jews were exiled from their ancestral homeland.

The main change in the latter period was the ending of sacrifices and the rising of Rabbis to deal with all religious matters as opposed to being just scholars. However, this was settled soon after 70 CE.

Answer:

Judaism has evolved as circumstances have necessitated. Here are just a few examples:

1) After the end of prophecy (some 2350 years ago), the Tanakh was sealed by a special Sanhedrin (Rabbinical court). It was the same Sanhedrin which placed our prayers in their permanent form (see 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.