In the Jewish Diaspora, Jews spread all over the world, and took their religion with them. It remains a small religion, with about 14 million adherents, or less than 1% that of Islam.
How Did Judaism Spread?
It spread because there was a problem when the United Nations declared that current Palestinian Muslim land would then be changed into a Jewish homeland which spiked war between the two and now some jews are spread all across the world.
Abraham go the people together and along and that's how it spread.
When they were told they spread it all over the world and some were killed because of this.