Evangelicals tend to adopt an unthinking view of scripture, which causes many problems - especially to people who fail to understand us and how we use the Bible.
Despite what some people claim, nobody simply believes what the Bible says: we all interpret. There are, therefore, two basic questions we need to ask.
The simple starting point is that the Bible is God's Eternal Word, and all of it is authoritative at all times in all places. But the Bible does not just speak eternal truths (if it does speak them at all...) - it is a record of a God Who speaks to particular people at particular times.
God told the Children of Israel to go into the Promised Land, then not to go, and then to go. This is not a contradiction: His command changed according to their behaviour and circumstances. What He wanted you to do ten years ago is almost certainly not the same as what He wants you to do today.
We also believe in progressive revelation. Most importantly, we believe that God is fully and finally revealed in the person of Jesus of Nazareth, Who was the Christ.
Progressive revelation is seen in the first chapters of the Bible. God gives all plants to Adam for food, and later tells him not to eat of the Tree of the Knowledge of Good and Evil. The later revelation (don't eat this one) over-rules the earlier relvelation (you can eat them all). If progressive revelation did not work, there would have been no sin and no fall. If we believe in teh fall, we must believe in progressive revelation.
Similarly, if we ignore the Old Testament commands about kosher food, or if we do any work on a Saturday, either we are being disobedient or we actually do believe in progressive revelation.
We have to interpret the Bible, and in that sense it is all interpreted. But many parts of the Bible are referred to and interpreted by other parts: stories are quoted, and propecies are fulfilled; images and principles from one era are picked up, re-cycled and re-interpreted in another.
So even if we simply want to affirm at we 'believe the Bible', and wish to avoid personal opinion at all costs, we cannpt avoid the need to engage with the issue of interpretation - indeed, the issue of multiple and sometimes contradictory interpretations.
The Bible does not come to us as a single text, but as a collection of multi-layered, inter-related texts that are intended to interpret, explain and illuminate each other.
It is widely recognised that 'a text out of a context is a pretext' - but determining the context is not a trivial task. What you consider to be the context will depend, to a degree, on your understanding o fhow the Bible came about and the details of how the text came to be inspired and written.
For example, is it valid to claim as the meaning of a text something that the original hearers and perhaps the human author could not have known and understood?
Part of our problem in reading the Bible is that there is a great deal of narrative, but little meta-narrative. We have stories, but we don't know why we have these stories (and not other stories), or why they were presented in this form (and not otherwise).
For example, are the stories in the Gospels selected because this is the way things were all the time, or because the events were noteworthy because they were unusual? Or, in some complicated way, a mixture of the two? And, if so, how do we distinguish the two types of story?
For example, when we read that Jesus healed all those who were brought to him, was this recorded as a confirmation of what we expect (Jesus always healed everyone, didn't He?), or is it recorded because this was a noteworthy event (on most occasions, some people were not healed by Jesus)?
In interpreting Paul's letters, we take account of the original recipients...
The meta-narrative sometimes colours our reading of the passage, but sometimes it completely determines the meaning. There are various passages where we are told what a person or group of people did, but we are not told whether they were right or wrong.
For example, how you read Acts chapter 1 rather depends on whether you believe that St Paul was the person God intended to replace Judas as the twelth apostle. Possibly this question never bothered you, but it was self-evidently true to the people who attended the church I grew up in.
Possibly more important is the question of cultural sensitivity. When we read in Acts chapter 17 about Paul's sermon on Mars Hill, are we being told we must practice cultural sensitivity (because we should follow Paul's example), or are we being warned to avoid it (because Paul tried this approach and failed - he should have stuck to preaching the gospel)?
Most of us are probably not conscious of the ambiguities inherent in these passages: for most of us, the answers to these questions is self-evident, so there is functionally no interpretative choice to be made.
But the fact remains that many other Christians interpret each of these passages differently to the way we do, and the reason for our choice of interpretation lies outside the Bible. The Bible does not tell us that Paul was or was not the intended replacement for Judas, or whether Jesus normally healed everybody. We can search the Bible for evidence to support each of these possibilities, but it comes down to weighing the evidence. And, for different people, different pieces of evidence carry different amounts of weight.
This is not to say that we can never determine what the Bible means: on all the important questions, it is crystal clear. But we must recognise that some doctrines are clearer than others, and some of the examples we follow are more securely established than others. A degree of humility is wise.
Crisis Centre