The Bible isn't a rulebook, and Christians cannot lift out of its context any passage from it, and still hope to gain a clear understanding of that passage.
It is important to understand that even the most fundamentalist Christian sects do not take the Bible wholly literally. The New Testament is two thousand years old, the old Testament much older. The Bible's cultural contexts, along with the translation at hand, is always taken into consideration by any Christian serious about understanding this vast and complex work.
To excerpt any isolated short passage from the Bible, and then claim for that passage absolute authority, is to fail to take the Bible on its own terms. If we wish to follow the word of God, then we must take the entirety of God's words into account. For example, when the Bible itself identifies some of its words as proverbs, it is bestowing upon those words less moral weight than other words that it identifies as commandments. The Bible itself tells us that some of its contents are songs, some visions, some histories, some dreams, some parables, and some commandments. The Bible itself also instructs Christians that New Testament moral directives supersede Old Testament moral directives. The Bible itself tells us that its moral principles supersede any of its moral "rules."
The context of any Bible passage is as integral to its meaning as the passage itself. It may be appropriate to give equal weight to each clause within a business contract, each step within a set of mechanical instructions, or each rule within a game rulebook. But the Bible itself tells us that the Bible is not a uniform document, with each passage spelling out something clear and specific, and all passages having equal value. The Bible is not a rulebook for being Christian. We would be foolish to fail to understand that not everything in the Bible is a commandment, and that Christians cannot take a small section of the Bible out of its larger context, and still hope to gain a clear understanding of that section. Isolating a clobber passage from its context, and then claiming a sort of moral helplessness because "it's in the Bible," is failing to take the Bible either literally or seriously.