I mean this as no offense at all, but if you want to bring the Bible into this (and I'm all for it), let's not play the game invented by those whom we agree are the idiots messing with the thermostat. I can prove any point you want me to with the Bible by misappropriating passages. I'm in the middle of writing a sermon right now, so I don't have the time to do a full explanation of that John passage you reference, but I could easily write pages upon pages about it. If an issue is that complex, our dialogue will only be fruitful if the full impact of that context is honored.
Also, every metaphor (by definition) breaks down at some point, so thermometer/thermostat one isn't going to be perfect. That being said, yes, the "manager" could mandate that the "right" temperature is 70, but imo, the manager gives us the HVAC system, but we have access to the thermostat- we can run it so hard that it breaks the system, or we can fight over 65 vs 72, or we can allow there to be a range. I agree with your assessment that often religion is perceived as being exclusive, and it often promotes that itself. But that doesn't make it valid.
To change metaphors, if you're at at game at FSU and the Noles are rolling, but you choose to cheer "Go Deacs" in the midst of their tomahawk chop, no one is going to hear your voice on television. But does that mean that the Noles fans are all right in their chanting? Of course not. We all know "Go Deacs" to be the true cry of victory, but the majority does not get to define the Truth, they can only twist it towards their ends.