Santo Subito said:
It says, "For where two or three are gathered together in My name, I am there in the midst of them."
He also said that many will come to Him on the Day of Judgment saying they cast out devils in His name, and He will say "Get away from me, I never knew you" ( as PIO221 just mentioned ).
Here He's speaking about people who use His name in a way that isn't pleasing to Him, but when casting out devils is involved, two or three AT LEAST are gathered in His name, aren't they? Is Christ contradicting Himself? Or is it possible you are a victim of Modernism and touchy-feeliness?
It is what Prots do to take a single saying of Christ or a single line from the Bible and read it literally. You have to understand it all taken together.
Christ established His Church on the rock of Peter. Therefore we know these are the true Christians. These are who He is talking about when he talks about two or three being gathered in His name. He's not talking about heretics and schismatics.
You do know, I'm sure, that the Church forbids taking part in the worship of Protestants, despite that they believe in Jesus Christ? Why is that, if all that matters is to be gathered in His name?