What is the relationship between God and empire in "Recessional" by Rudyard Kipling?

This poem shows that even when empires fall, God remains. This stanza especially, shows this relationship:

"The tumult and the shouting dies;

The Captains and the Kings depart:

Still stands Thine ancient sacrifice,

An humble and a contrite heart.

Lord God of Hosts, be with us yet,

Lest we forget-lest we forget!"

It shows that a war has ended (the shouting has died) and that the empire has left (the captain and the Kings depart) but that God is still present (Still stands Thine ancient sacrifice etc). We know he is referring to God here, because "Thine" is with a capital T which represents something holy.