Many people are mislead by "experts" who have told them what they believe the Bible says. It is essential to read the Bible for yourself so that if your leader has false motives or just innocently makes a mistake, you do not end up on a wrong path. Surely the God who created the Universe was capable of communicating in a way that even less educated people could understand!
I believe that the Bible, as originally written, is completely true, because I believe the authors* were guided by the Holy Spirit, and God is truth. However, I worship God, not the Bible. The creation is another revelation from God: a more universal one that can be seen even by people who cannot read the Bible. However, I do not worship the creation, either. God may reveal himself to me personally, through the advice of wise friends, an inclination of my heart, odd circumstances, or a feeling of being led to make a certain choice. I must be careful not to allow myself to rely upon my feelings so much that I become my own God. Because truth is reliable, I can test my interpretation of these three ways in which God reveals himself against one another. If what I think the Bible says directly contradicts science, or if what I believe God is directing me to do is inconsistent with what God, in the Bible, said would please Him, I need to revisit the situation, because I can be certain that I have made a mistake in interpreting at least one of these ways in which God speaks.
When we study the Bible, I believe we need to read it from the perspective of the people to whom it was originally written. What problems and opportunities was the writer addressing and what was taking place in the lives of the recipients? What message is the writer trying to convey, both in the entire book or letter and in the specific section I am studying? For example, a poem David wrote, pouring out his heart about his feelings of guilt after Nathan confronted him with his sin with Bathsheba, is often used to support the doctrine of total hereditary depravity. But we know that David's poems often contain hyperbole - the purpose of this poem is to let us know that David recognized how terribly wrong he was. Because he repented, he was reconciled to God, despite the magnitude of his sin; therefore, we can have confidence that no matter what we do, we also can be reconciled with God. In the same way, I have seen Proverbs misused to condemn others. Proverbs are "wise sayings" that are generally useful for life, but they are not promises from God. That was not the purpose for which they were written, and the original readers would not have viewed them as promises.
On the other hand, there are many historical books in the Old and New Testaments that describe miracles that were performed by Moses, prophets, Jesus, and the Apostles in order to prove that their messages were from God. If I were to deny that these miracles actually took place, I would be denying the proof that their messages were really from God. I would also be denying that the Bible is truth from God. Believing that the historical books are describing things that actually happened matters. Note however that not all historical books tell events in chronological order: some organize events into themes. Also, we need to be aware that the original languages in which the Bible was written had very small vocabularies, so translations can easily lead to misinterpretations. And, the people of the day may have thought of the world quite differently from how we think of it.
How can we who do not have a degree in ancient history, Bible, etc. know what was happening in the lives of the people to whom and about whom various books of the Bible were written, so that we can read them in their appropriate context? I believe it helps to read a letter or short prophetic book in its entirety first, before studying it in detail, so that we appreciate the flow and the tone. These are some very well done videos that can help you if you want a good succinct context before reading a section of the Bible. Here is Philemon, as an example. Thanks for the link, Howard!
Commentaries can sometimes have agendas, so I read them only AFTER I form ideas of my own, based upon what I already know about who God is and what He desires of me (such as mercy).
*Translators are not necessarily similarly guided, which explains why they sometimes disagree. A few copying errors are likely to have occurred, but the Dead Sea scrolls prove that the scriptures were remarkably accurately preserved over the centuries.