“And Judaism is a religion, not an ethnicity. Anyone can become Jewish.”
It is a belief system not a race.
That's not exactly true.
Many if not most Jews are now secular. Ergo, it may not be a "race" per se, but it is a bloodline and heritage.
You are correct, but there is also an ethnicity component.
Hence, “Tribe”. Some of my family take offense at this, and it can be mean. But so can any word in context.