"Not one stone upon another will be left here that will not be thrown down," Luke 21:6.
That's Jesus talking about the second Jerusalem temple. This second temple had been built when Judah and Israel returned to the land after their captivities. We remember the first temple had been destroyed when the nation of Judah ended since the people broke their covenant with God. The second temple then became the place for all the sacrifices required in the (broken) covenant. Jesus now prophesied this temple would fall like the first. And the need for its sacrifices would go away for ever. Something new dawned over the horizon. Something new that called for a temple made up of human beings, not brick and mortar. It called for a final sacrifice announcing a new covenant.
We meet with a brother or sister today founded on something eternal and new. And together we give thanks to God for a new covenant heralding his kingdom in Christ.