It is important that the beliefs and practices of our Christian communities be governed by the explicit teaching of scripture rather than by unconsciously (or perhaps semi-consciously) held unwritten rules that actually contradict these written rules. In most cases, Christians exist in a state of theological schizophrenia according to which we are governed simultaneously (to some degree) by both.
The philosopher Slavoj Zizek makes this point in a hypothetical Communist party meeting headed by Stalin. Suppose a party member were to stand up during Stalin's speech and criticize Stalin. Next, suppose a second person stood up to rebuke the malcontent with something like "are you crazy? You can't criticize comrade Stalin!" The second person would be the first to be arrested because he has articulated the essential unwritten rule, which itself supposedly contradicts the more explicitly held belief that obviously Stalin is not infallible. It is by articulating this essential yet unconscious belief that its absurdity is so readily exposed.
Unfortunately, in many theological communities, historically important theologians and confessions are immune to such criticism. Essential though creeds and confessions indeed are (and we must never forget that we all hold to our own creed or confession, which is no less subject to codification than any other), we must always be ready to soberly examine whether or not or to what extent our confessions line up with scripture, and be willing to relegate primary, secondary, tertiary, etc. issues their proper place in our hierarchy of doctrine.
Perhaps more disturbing is the intellectual dishonesty of historical revisionism, according to which we read our own doctrines into historically important theologians or confessions in order to lend them the appearance of historical pedigree. One should not be embarrassed that such and such a creed or theologian disagreed with our perspective. We should also not be more exclusivist in our historical confessions than its original authors were. For example, many Westminster divines rejected positions codified in the WCF yet were not therefore anathematized or ostracized by their contemporaries. Though we ought to hold to such confessions, we must always be ready and willing to tweak them when necessary.