Sorry, don’t have much time to expound on this right now, but listen to this sermon (really more of a “talk”) when you get time!
Why? Because this “What is…?” talk is from someone with a lot of credibility with the “The Church of Christ IS The Kingdom, inclusively and exclusively” group… and he basically demolishes that concept.
Is he THE John Smith who wrote “My Mother Played the Piano”? Yes.
Here are the links —
What Is a Restoration Church? (Full talk by John Smith – 42 minutes)