In the last post we examined the traditional Evangelical hermeneutical method, where inerrancy functions as a key control in interpretation. As I mentioned, though, others don't take this approach. Another very common framework is to interpret using the 'rule of faith.'
Those who hold this view interpret within the 'box' of creedal orthodoxy. Scripture is still fully authoritative in the life of the church, but the way we interpret individual passages is left open as long as one does not deny the basic claims of the creeds of the early church (think Nicea or Chalcedon). Most questions related to historicity of events in the Bible are left open. Thus the boundary has been pushed out further than the traditional Evangelical boundary (inerrancy) and is also different in nature.
When working under the traditional definition of inerrancy, the text of Scripture forms your boundary. You identify its genre and then affirm everything that the text affirms. The rule of faith places the boundary in church traditions, which were based on Scripture. For that reason, some will criticize this method of interpretation, arguing that it elevates the creeds of the early church to or even above the level of Scripture. However, it response, it would be said that the creeds are based on Scripture thus the objection doesn't carry as much weight as it may initially seem to carry.
Another charge leveled against the rule of faith is that it is arbitrary. Which creeds form the rule of faith and why? Typically opponents will then point to the possible danger. If all we hold to are creedal definitions, and we can, for example, deny the historicity of almost every pericope in the gospels, then what are we left with? Haven't we eroded the supports to the bridge making it unsound? Are we left with anything that is reasonable to place our trust and hope in? With that said, most detractors of this view will realize that most proponents of the rule of faith don't go down that path, but they still worry about the slippery slope.
Let's look at our Mark 2:26 example from last post to see how one would use the rule of faith to guide interpretation of a particular text. You would have no problem with coming to the conclusion that Mark erred in his identification of Abiathar as high priest. What they are bound to affirm depends. At minimum they must affirm the general thrust of the entire section - Jesus is the Messiah. All also would probably (but not necessarily) suggest that we must also affirm whatever implications this passage has on sabbath/Lord's day observance. There is openness, when using the rule of faith, to have one's understanding of the nature Scripture changed based on what one sees in the text.
 This is true even those within this position who accept a redefined inerrancy like Kent Sparks does. He claims that while human authors erred God didn't. He accommodated himself to an errant human witness, and basically said, 'that guy speaks for me in what he wrote.'