Theists: Under whose authority is a "bible study" group successfully arriving at the correct answer?

In the Bible study groups that I've learned the most from, usually we are seeking greater wisdom and enlightenment rather than correct and incorrect answers. The best method for Bible study is to simply have everyone read a passage or related passages, and to talk about what we think it means. Usually after a little comparison and study, the answer is obvious and unanimous. When it isn't, we left it alone and prayed on it some more. The Bible is the only true authority in any church I've been in--everyone else you consult about it is merely giving their view about what is contained in that book. Even the preacher giving the sermon will admit that he can make mistakes.

First Holy Spirit

Second bible says scripture interprets scripture

For Catholics that would be at a parish level, But all information has always come from the Vatican and its leadership under all Popes from the 2nd one forward for it is Jesus Christ that leads them unto all this TRUTH.