This is an old post that I am putting up again for comment and consideration...
John "Rabbi" Duncan was a minister in Scotland and professor of Hebrew at New College, Edinburgh, in the 19th Century. There is an interesting anecdote about a conversation he had with Dr. Muir of Glasgow. They discussed the appropriateness of the title "Theotokos", Mother of God, for Mary. Duncan was in favour of it, Muir denounced it as "Popish blasphemy".
Moody Stuart comments that:
"Dr. Muir revered the Bible, but no authority besides, and he must have everything direct and clear, with no mystery about it".
After debating the matter for two hours Muir left. And John Duncan said:
"That man owes much to divine grace; except for grace Dr. Muir would have been a Socinian."
I take it that there was no complaint about having no authority beside the Bible. The problem is with the hidden assumption about how to read and interpret the Bible. In which case it is not really a commitment to sola scriptura at all. The appeal to sola scriptura is masking a mindset that doesn't really take God at his Word but assumes that he must speak and reveal himself in a particular way.
A few years back I gave some seminars on the Trinity at Word Alive. I chatted one afternoon with a student who believed that the Father and Son were both God, and distinct persons, but that the Spirit had no distinct personal nature. When we talked it over it became clear that he expected the Bible to explain God's triune nature in a set way (a bit like the creeds do). When he couldn't find those sorts of statements he wasn't convinced that the doctrine was really there. But he was mistaken. The Bible is a two part covenant book about the effected rescue plan of the triune God. He reveals his identity as he saves us, and in that rescue plan each person works together and distinctly as God in his infinite wisdom has seen fit.
It makes all the difference not only to submit to God's Word but to submit to it as God has given it to us without smuggling in our own assumptions about how he must reveal himself.
Or as the Westminster Confession I:vi puts it:
"The whole counsel of God concerning all things necessary for His own glory, man's salvation, faith and life, is either expressly set down in Scripture, or by good and necessary consequence may be deduced from Scripture"