The entire narrative of the Hebrew Bible is built around God's promise of the land to Abraham's descendants.
Through centuries of exile, Jewish hopes and prayers were focused on the Promised Land.
Since the beginning of modern Zionism, some Jews have stood in opposition to it.
Medieval kabbalah offers various approaches to the Land of Israel.
Ancient/Medieval Jewish History
Because most Jews of this period lived in the Diaspora, Israel was an abstract concept.
In the Bible, possession of the Land of Israel is tied to moral behavior.
In rabbinic literature, the Land was of primary importance--even as the Diaspora grew.