The great multitude that no man could number is the Children of Israel and the Tribe of Judah.  

The Body of Christ is the Children of Israel and the Tribe of Judah.
The Church is the Children of Israel and the Tribe of Judah
The Bride of Christ, New Jerusalem is the Children of Israel and the Tribe of Judah.

For GOD so loved the world of the Children of Israel and the Tribe of Judah, that he gave his only begotten son.  That whosoever of the Children of Israel and theTribe of Judah believes on him, shall not perish, but shall have everlasting life.