Actually, their authority exists whether or not some jumped-up self-appointed "preacher" recognizes it or not.
That wasn’t what I was saying, and I agree with you. However, I do recognize the poster’s right to believe in whatever he wants to believe. We can try to reach others with our message, but we can’t force anyone to believe anything. That is between them and God.
However, I am reminded of something Fulton J. Sheen wrote after a trip to the Far East:
Catholic missionaries, he thought, “should start with what is good in the religions they find in their countries as Our Lord started with a drink- of cold water in converting a Samaritanas Claudia began with a dream in understanding Christ far better than a rational- husband, and as Paul began with an inscription to a pagan deity to convert two souls in Athens.”
And as the discussion originally began with St. Patrick, let us remember his methods in converting the Irish. Each person needs to be communicated to on their own terms. Bishop Sheen was famous for his ability to attract converts. We could all learn a lesson from that line of thinking in our religious conversations with non-Catholics.