When Christians gather Christ is in their midst, of course.
This does not mean that when 10,000 Christians gather they are an amorphous mass - are you denying that Paul clearly gave Timothy instructions on how to run a Christian church and how to vet pastors?
Or that Paul described the Church as a body with various members with different tasks and responsibilities?
Are you denying that Christians in the NT period exercised discipline over their members, held councils, gave decrees, etc.?
Are you basically saying that witness of the Apostles and the NT is useless?
I'm basically saying that you would have made a wonderful Pharisee....
Not at all.
But I, at least, am saying that I strongly suspect that God's priorities in such matters are rather different from yours.
Organization etc. can become even very NECESSARY.
But it's not to be the focus. You seem to have made it your focus.
NECESSARY . . .
ALMOST
as in necessary evil.
GOD INSISTS ON INTIMATE DIALOGUE WITH EACH BELIEVER. Institutions tend to muddy that, water it down and obstruct it rather than aid it as they were supposed to do.