That's not to say they're un-biblical. Rather, what many traditional churches are is extra-biblical. There's a difference. Extra-biblical refers to things that are outside the bible (i.e., owning buildings and many functions of ministry) while un-biblical refers to things that are actually opposed to the bible (blending Christian worship with pagan worship, for example).
Problems creep in when churches confuse their extra-biblical traditions (which are not wrong in and of themselves) with actual biblical teaching. I submit that this is a very real problem we need to be careful of. I further submit that the Church of Christ is particularly prone to this danger.
Examples of this confusing of extra-biblical traditions with biblical teaching are the so-called "5 Steps of Salvation" and "5 Acts of Worship." These catalogues of teaching are useful and helpful as summaries of biblical teaching, but since scripture nowhere presents these in such helpful lists, we must see them for what they are--traditions we have created to systematize things the bible itself does not systematize. Are they wrong? No--they correctly summarize key teachings from the bible. But are they "biblical"? Not if we are going to "speak where the bible speaks and be silent where the bible is silent." These lists are not un-biblical though; just extra-biblical.
We're prone to this danger for two reasons, in my opinion, both based on the way we interpret the bible. We have been taught an approach to interpreting the bible that is not spelled out in the bible itself. Does this mean that the way we read and interpret the bible is wrong? Again, no--but it does mean we need to be careful with the bible.
For example, the old "command, example, an necessary inference" is useful--but very vague and open. Which commands? Which examples? And "necessary inference" becomes a catch-all for whatever we want to see in the bible to bind on someone else.
Our way of reading and interpreting the bible forces principles of intrepretation onto the text that the text itself does not demand. It also runs the risk of creating a new law out of the new covenant rather than creating the conditions for grace to be revealed into our lives.
Frank Viola's book, Finding Organic Church, is helping me re-learn what the bible actually teaches about "church." And that's a good thing. A church can do no better than to go to the bible looking for bibical answers to biblical questions. Our task is to struggle with scripture in its fullness, to hear the old stories from the bible, the prophetic experiences, the deep laments of the psalms, the drama of the gospels, and the wisdom of the letters.
We lose this grander narrative when we try to systematize and organize the bible into categories and lists.
The bible teaches us as we allow it to. We need to read, study, and meditate--all with a movement towards obedience in our lives. This is how we find a biblical church--not by extracting things out of the bible to put into practice, but by being shaped and formed by the bible in all of its beauty, chaos, and truth.