You will not like the answer, but it is indisputably true.
Because Sola scriptura "bible alone" itself is the problem.
Bible alone is not biblical!
Where in the bible does it say that something has to be in the bible to be true?
Bible alone is not logical!
And because it is not in the bible, it is therefore false in logic too - if the ultimate truth is "all necessary truth is contained in the bible (people even isagree on the meaning of sola scriptura) - then that ultimate truth should be in the bible, and it is not, so sola scriptura is logically false.
Bible alone is not historic!
When Jesus gave us the new covenant, he said "do this" not "write this". So few of the apostles did write, and what we know as the new testament was a couple of centuries in the making. For the early Christians truth was passed by word of mouth and tradition which is why apostle Paul tells you to stay hold true to the traditions told by "word of mouth and scripture" Scripture for Paul was the OT. The NT did not then exist.
So what do we know?
The bible (as for example Pauls letters) are hard to understand on its own. Even Peter says so in 2 peter 3:16
We are urged against private interpretation proverbs 3-5
Asking the spirit for guidance is not the answer either...
The idea that learned men asking the holy spirit for guidance will come to the same conclusion is proven totally false.
By the fact of tens of thousands of protestant denominations and schisms, and who knows how many "one man" denominations preaching "their version" of the truth. The holy spirit has only one truth, so most who say so are misguided.
So what is the truth?
The bible says "the pillar and foundation of truth is the church" NOT the bible..1 timothy 3:15
So then you ask which church? and the answer can hardly be any of the recent sects, formed as a fracture from a recent sect, destined to fracture in to more.
See the thread "heartbreaking" to see what happens when man ( a head pastor) is allowed to decide doctrine
http://christianchat.com/bible-discussion-forum/109003-just-so-heartbreaking.html
Luther abhorred this saying every milkmaid had their own doctrine!
He said towards the end of his life:
“There are as many sects now and beliefs as there are heads. This fellow has nothing to do with baptism. Another one denies the sacraments. A third believes there is another world between this one and the last day. Some teach that Christ is not God. Some say this, some say that. There is no rustic so rude that if he dreams or fancies anything believes it must be the whisper of the Holy Spirit and that he himself must be a prophet.”
Luther was even more critical of the non denominational one man factions arising from self interpretation.
"In matters of faith, to be sure, each Christian is for himself Pope and Church.” “There will be the greatest confusion. Nobody will allow himself to be led by another man’s doctrine or authority. Everyone will be his own rabbi: hence, the greatest scandals.”
Notice the arguments on this forum!
He concludes wryly:
"If God had not closed my eyes, and if I had foreseen these scandals, I would never have begun to teach the gospel."
"If the world lasts, it will be necessary, on account of the differing interpretations of Scripture which now exist, that to preserve the unity of faith, we should receive the Catholic councils and decrees and fly to them for refuge."
That lack of authority in the light of disputes and clear ambiguities is why there are so many fractures
So the question is authority? Who speaks on behalf of the church?
The mark of a true denomination is one whose doctrine has lasted essentially unchanged for millenia.
There is only one. The early church was sacramental. Liturgical. Believed in real presence. Authority of bishops and succession. So conclude where logic takes you. You will not like the answer.