God’s gifts to us are his Word and the local churches.
The fact that there are self-governing local churches at all is astounding in light of how God interacted with Israel. In Israel, God had one dwelling place, and they were bound by His law to come up to that dwelling place three times a year.
But after the fall of Israel, God sent Paul out to establish local churches. He had him write to some of these churches, even ones he hadn’t visited.
This is important because a multiplicity of copies of God’s Word among a multiplicity of local churches is the best way of preserving His truth.