The classic Evangelical position here is that believing on Jesus Christ personally for salvation of your eternal life, without mediator except for Him, by definition puts you in His church. Details of whom the Lord wants you to affiliate with on earth about the connected collective body responsibilities would correspondingly be absent, except that it should be believers, and the more sincere the better.
That is, believers in Him. It is SOOOOO easy for an ostensible worship organization to become believers in themselves. But pride as always goes before destruction. In many cases spiritual destruction. The earthly effects and heavenly rewards of any Christ belief that may be present are minimized in such a situation, which tickles the devil and grieves God.
There’s gold in them thar hills (of your post).