It is common for Christians and others to attempt to “prove” a particular point by referring to some passage in the Bible that, they claim, supports their point. Of course, if the passage in question has been properly understood then this can be a constructive technique to adopt but if the passage in question has not been properly understood then the consequences are foolishness.
One important distinction that needs to be kept in mind when reading the Bible (or any other text) is the distinction between descriptive passages and doctrinal passages, so what are these things?
Put simplistically a descriptive passage tells us what actually happened in a particular situation, while a doctrinal passage tells us what ought to happen as a general rule. Descriptive passages and doctrinal passages can both be used as teaching or informative passages but they teach us different things or, put differently, they give us different kinds of information.
A descriptive passage teaches us about things that have already occurred and informs us what happened in a particular time and place. A doctrinal passage teaches us general truths or rules or guidelines that we should apply to our own lives or beliefs.
However the foregoing definitions are an oversimplification: Sometimes a descriptive passage might contain both descriptive elements and doctrinal elements. Furthermore even when a doctrine is clearly stated it is not necessarily universally applicable because some doctrines will only apply to particular places or occassions.
Confusion and problems can occur when somebody attempts to extract a doctrine from a descriptive passage that has no doctrinal content or, alternatively, when somebody takes a doctrine that was applicable only to a particular time and place and attempts to apply it as a general rule.
Let us just try and consolidate this idea with a brief example: According to the Bible it is acceptable for a man to commit adultery ... yes or no? Well King David was a good servant of God, and a great king and he committed adultery and he is respected as a person who God described as “a man after my own heart”. So if this man, whose heart was like God's, committed adultery then adultery must be acceptable. Of course anybody who has read the whole story will know that actually God was not at all pleased about what King David did and punished him for his misconduct. The story about King David, Bathsheba and Uriah is a story about what they actually did, not what they ought to have done. In this particular incident we know that God was displeased with King David because the story continues to tell us so but in other cases we are not necessarily told what God thought about a particular person's actions. The Bible accepted by Christians is not a particularly long book and it does not attempt to tell us every detail of every situation, nor would that even be possible. Instead we have been given the essential parts of a big story from which we must try to extract the general rules which we can then apply to our own lives. In some cases we have also been given specific instructions.
When we study the bible it is important therefore to recognise which passages have some doctrinal content and which passages are purely descriptive.