Oddly, some people seemingly expect the progression to go like this
...
But of course that's mistaken. That's because the acorn doesn't just grow. It develops into a sprout, a sprig, a sapling, a tree. After it's been growing hundreds of years, it develops hugely, not just in size and also in complexity.
Maybe you think this is childish ---maybe too rustic. But it's the best way I know to explain this. My impression is that some people look at the Church at the dawn of the Church Age (before 100 AD) and expect to see the exact same thing 1,000 years later, but bigger; and 1,000 years forward from that, but bigger yet. They seem perturbed to see development. They certainly don't expect development. They just expect re-sizing.
See what I mean?
Their implicit expectation that the Church as an earthly society ought not to look different whether it's 50 AD, 500 AD or 1000 AD is baffling to me.
I love the Church. I expect it to be fruitful (I'm switching the metaphor here from an oak tree to a grape vine.) I expect the Lord has always protected, and always will protect, this Vine which His right hand has planted.
The problem with your illustration, is you are not the original seed sown, you are the tares. See the parable of the wheat and the tares, Matt. 13.
And this video, “Tares among the Wheat”
https://www.youtube.com/watch?v=-aiHcghIdjM
Your sycretist church-state, paganized form of Christianity “tree,” bears no resemblance to the church in the original church in the book of Acts.