As the early post Joshua Israelites had no earthly leader went about conquering in the name of God, so too did the early Church.
Now after the death of Joshua it came to pass, that the children of Israel asked the LORD, saying, Who shall go up for us against the Canaanites first, to fight against them? And the LORD said, Judah shall go up: behold, I have delivered the land into his hand.
Judges 1:1,2
And I saw, and behold a white horse:
and he that sat on him had a bow;
and a crown was given unto him:
and he went forth conquering, and to conquer.
Revelation 6:2