As a law student, my favorite topic was statutory interpretation. Statutory interpretation is the process by which a judge will interpret the law and decide how to apply it in a given situation. As it turns out, not only was it my favourite topic, it happens to be the one I have most used in my Christian life. This is because the Bible is a lot like the law.
I suppose in some ways that goes without saying. Even the Torah is referred to as "the law". But you would be surprised at how many people believe the opposite is true! Whereas the Bible deserves to be treated as seriously as a law book, a significant number of people treat it as if it isn't a book at all. As if it doesn't use plain language, but pure poetry. As if it is not a book of words, but of pictures. As if one can read as many of their own opinions into a Bible as they can write their own opinions in their diary! "The Bible is open to interpretation", they say. To these people, I say yes, it is. All written words are open to interpretation. It's called reading. But again, just as a law is open to a definite interpretation, so is the Bible.
I want you to imagine a court case. There's a big, scary judge sat in front of you, and you must convince him not to send you to prison. You have to choose a lawyer. Who do you choose? A lawyer who will argue "hey, my client is still following the law, he's just interpreting it differently to you", or a lawyer who will say to the judge "this is what my client did, this is what the law says, my client obeyed the law, let him go"? You're obviously not going to choose the berk whose argument renders the law as useless as the paper it's printed on, you're going to choose the guy who knows his stuff!
In the same way, those who claim the Bible is open for interpretation seriously undermine what the Bible is. It ceases to be a book and instead becomes an ink-stained block of dead trees. But just as a good lawyer knows the law, a good Christian knows his Bible.
What's interesting is that those who most often argue that the Bible is open for interpretation usually argue as if it isn't. Atheists who claim the Bible is too ambiguous seem quite happy to argue about it when they think they can make it say something evil, or contradictory, or unscientific. False denominations who argue the Bible is open to interpretation seem quite happy to argue in defence of their bad doctrines. As vehement as people are in saying the Bible is open to interpretation, no one is especially good at acting as if it is. The whole "different interpretations" argument is almost always just a desperate attempt to defend an interpretation that is blatantly wrong.
Whether an unbeliever or a believer, it is vital to treat the Bible as what it is: A book. It is a book with a meaning, and it means what it says, and says what it means. It is open to interpretation, because all written works are, but there are correct ways to interpret things, and incorrect ways to interpret things. Treat the Bible as the book it is, or risk looking as foolish as a lawyer trying to convince a judge to let their client off the hook because the client is simply abiding by the same law in a different way.