Luke 9:49 John answered, "Master, we saw a man casting out demons in your name, and we forbade him, because he does not follow with us."50 But Jesus said to him, "Do not forbid him; for he that is not against you is for you."
Interesting. Do you think that if these folks were "against" Jesus, that Jesus would approve of them?
Obviously not. The Pharisees (in general) were against JESUS, and He certainly didn't approve of them.
If they were doing in contradiction to what the Apostles taught, is that just hunky dory? Or is the message given to them optional?
I believe that this passage is telling us that what is important is doing the will of JESUS, and that there is no need to be under any particular earthly authority to do it.
If we were all capable of discerning this will without assistance from those set up to teach us, I would agree.
Which returns us once again to the idea that Protestants have that they will be led to truth individually by the Holy Spirit.
Doing the will of Jesus is certainly the important thing, but that does not mean we do not need guidance. So He left us a guide.
Incidentally, your use of the phrase "particular earthly authority" is interesting. Given your hypotheses, what purpose does any earthly authority serve? I can see someone like me submitting to an authority that I thought was, well, authoritative. But since you reserve the right to determine is your "authority" is reading the Bible correctly, what is the point?
SD
Did you read the posting by al_c this morning? It says essentially the same thing, from a Catholic source no less.