I think the final authority for anything, religon or otherwise, will, in fact, always be your mind.
I think that could be said to be a fair statement in many ways. I cannot say that I necessarily agree with it wholeheartedly because I do believe more is at work but often your mind is what interprets what you read and hear.However, I think the ultimate authority is indeed God (and that includes the Bible IMHO). Here's why.I go to the very last part of Luke 11.Luke 11:51
Woe unto you, lawyers! for ye have taken away the key of knowledge: ye entered not in yourselves, and them that were entering in ye hindered.
Christ is talking to many of the scribes and Pharisees here but I believe strongly that he reaches out to us with this verse. I am an English major myself and a big part of English falls under the critical realm, as does many of the interpretations of the Bible. We, as a collective group, love to think that we're somehow smarter and better interpreters (lawyers) of the Bible. I think you'll agree that there are many interpretations of the Bible out there be it KJV, NIV, NRSV, and so on or be it liberal, conservative and so on. Your mind might be the earthly authority but God is the final authority. His commands are revealed through the Bible, Christ's teachings, the Holy Spirit, and our own personal experiences.It might be someone else trying to speak, such as satan at times. I believe that with prayer this can quickly be overcome. Jesus constantly taught us in the Bible to look past the physical realm and into the spiritual. Take the lessons given to Nicodemus and others in the Gospels. So many times the students of Christ's words looked at the physical - this includes the idea of being born again ("How can a man be born when he is old? can he enter the second time into his mother's womb, and be born?" - John 3:4). Nicodemus took the scholary, "lawyeristic" approach here.Christ provides for the authority of the Old Testament often as God's word:Matthew 5:17
Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil.
John 7 also has some more insight into the question. 15-17
And the Jews marvelled, saying, How knoweth this man letters, having never learned?Jesus answered them, and said, My doctrine is not mine, but his that sent me.If any man will do his will, he shall know of the doctrine, whether it be of God, or whether I speak of myself.
I could go on and I'm sure you're quite tired of reading at this point but I do believe that God is the final authority. He has given us tools, such as the Bible, in which he reveals things but it takes more than just simply reading the Bible to get it right.