the liberty of opinions

I would like to start this post off by warning you that I might be taking the following statement out of context - but bare with me for this is how my mind works.
In Poltical Science we are studying John Stuart Mill's defence on liberty - how the liberty of opinions can be useful. The third statement reads: Even if recieved opinion is whole truth, it will degenerate into mere prejudice or dogma if not exposed to conflict with other opinions.
When I read this statement all I could think of was how it relates with the different denominations within the church of Christ. Do you think that it is necessary to have a conflict of opinions so that the truth, which we as Christians hold, does not simply become a dogma or mere prejudice? Must we challenge eachother in the controversial aspects of our faith so that we are constantly challenged to continously search for the answers and not be satisfied to settle for less? Does the liberty of opinions within our faith help keep the truth alive?
If the answer to these questions is yes, then the negative connotation that is often connected with denominations is wrongly felt. We have the option to use it as a tool instead of a hinderance.
"As iron sharpens iron, so one man sharpens another." - Proverbs 27:17