In the earliest parts of the Old Testament, the “chosen people” are called Israelites or Hebrews. Only in the later books—Jeremiah, Ezra, Esther, and others—does the word Jew come into use.
The word comes from the tribe of Judah, which occupied the largest region of Israel, the region that included
Jerusalem, the capital.
When the northern tribes were conquered and scattered by the Assyrian Empire, Judah stood out as the most important tribe. Jew in the original sense means “one from Judah.”
In the New Testament, the terms Israelite and Hebrew are hardly ever used. Israel as a political state did not exist, and the name that the ruling Romans gave to the area was “Judea.”