Anybody is welcome at a Catholic mass now. You just can’t take communion.
Bingo, this is the answer I've been looking for. I am a protestant. I've gone to Catholic mass with friends. It has never occurred to me that they should modify their communion for me.
What I believe is different than what my Catholic friends believe, but it has never occurred to me that they should change for me.
I wish I knew what God considers important; and which is fluff; and which is "good, but not required." But I guess that if we could figure that out, there wouldn't be different religions.