Our Lord and Savior, Christ Jesus is the head of the body, the body being his believers, who obey God through faith in Christ. He didn't ever say He was given a body of numerous sects or of heirarchal brotherhoods. Rather we are all members of the same body through faith in Him.
We disagree with one another when between two or more parties of the disagreement, one if not both happen to be out of fellowship with Him. At that point, our soul, still indwelt by the Holy Spirit, but no longer in fellowship with Him, falls back onto scarred thinking processes. While we rationalize independent of Him, we also sin.
So, which of the 20,000+ Protestant sects is the one that is not "out of fellowship with Him"?
-A8
So, you acknowledge that it is entirely possible that EVERY Protestant denomination is wrong.