A better analogy would be that the same way as one can determine more about a person’s politics by the nature of their position on Romney, so one can determine more about a person’s theology based on knowing their denomination position on Jesus Christ.
Your analogy would be more like claiming to know about a person's politics based on their political party affiliation.
Nope. Take for example, Alamo-girl. She said that she’s a Baptist, for the most part. And an SBC at that.
Because of that, I can surmise that she leans toward baptism by immersion.
Now, because she says that she is a follower of Jesus Christ, I can’t necessarily come to that conclusion.
So, knowing one’s denomination provides a bit of predictability one wouldn’t otherwise have.
I was called once upon a time to the bedside of a young paratrooper who’d taken a round in the spine during one of our wars, and was being prepared for surgery. I was told he was a Roman Catholic. We had no priest within flight distance of our location due to unfriendly fire between him and me.
However, based on the RC denomination, I was able to go prepared with some material and some prayers that I knew would be a comfort to him. We spoke and prayed before the surgery as much as he was able...he was very weak. He thanked me, mm...and then he squeezed my hand. It’s one of my cherished battlefield memories. Thank God, he survived. He was air-evac’ed right after the surgery.
We never crossed paths again, but years later, I lifted up this story and his name in a group of troops, and one of them knew him. He was disabled, but not immobilized. God brought us together that day. This old bapto-charis-methodist was able to minister.