The Reformers were right to cry, "Sola Scriptura!"
In their focus upon salvation, the Reformers (Luther, Calvin, etc.) looked in the bible and found that sinners are declared just by God's grace based upon their faith. This is what the bible teaches, and therefore they believed it.
The Reformers, sadly, "missed the boat" when it comes to what the bible tells us about the church. While the Protestant church that came out of the Reformation was far more biblical than the Roman Catholic Church, it still had far to go to even come close to following the scriptures.
So, what would the church look like today if we really applied the concept of sola scriptura to the church? Would we even dare to do so?
If exceptionally skilled men like Martin Luther and John Calvin could miss (or purposely ignore) at least some of what the bible says about the church, could we get it right?
I believe we can. Applying sola scriptura to the church is actually quite simple. The real issue is whether or not we'll actually do it.
The bible is not only inspired, true, and authoritative. It is also sufficient. It is sufficient for both faith and practice. This includes the practice of not just the individual, but also the church.
So how do we know how the church should function? We look to the pages of scripture. This is where we must be careful. If we simply follow the commands of scripture regarding the church, we will still have many questions. However, if we will follow both what is commanded and what is modeled, then we won't have many questions at all (if any).
If we will look to the pages, for example, of Acts and I Corinthians, we will see church life modeled for us. We see much that is good and some that is ugly. When we apply sola scriptura to these books and try to function as they did, we will know what to do.
It is when we get away from what is modeled that we begin to have problems. Many modern churches that say they hold to sola scriptura have to deal with problems the bible never addresses because they do not follow its model. For example, a modern, traditional church may wonder whether or not they should add an addition to their church building. How can they know? Well, the bible won't tell them because no churches in the bible ever built buildings.
If we are going to say we believe in sola scriptura, then let's live this out. We do best by following both what is commanded and what is modeled in scripture.