In fact, throughout all sixty-six books of the Bible the writers mean what they say. Go ahead and open to any passage in any book and begin reading. Does it ever seem as if the writers either do not mean what they say or that they are just fooling around? The answer is no. The tone used by all the writers is serious. They write with purpose. They desire that their meaning be understood. What they have to say matters.
At no point do the writers say, "Ignore this if you want. It's up to you." Likewise, they do not write, "I'm joking. Just pretend I didn't say this at all." All the writings, Old Testament and New, convey serious meaning. In fact, every word matters. In Revelation chapter 22, right near the end of the Bible, we read the following in verses 18-19:
I warn everyone who hears the words of the prophecy of this scroll: If anyone adds anything to them, God will add to that person the plagues described in this scroll. And if anyone takes words away from this scroll of prophecy, God will take away from that person any share in the tree of life and in the Holy City, which are described in this scroll.
God takes the Bible seriously. If we doubt this just look at what Jesus said in Matthew 5:17-18, "Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished." Thankfully for us Jesus fulfilled the Law; because of that we do not have to. The point for the purposes of this post, however, is that none of God's word can be ignored.
God's message to this world is important. Because of that, the Bible is important. The Biblical writers understood this. Their goal was to convey this message clearly to their readers/listeners. Due to the gravity of what they wrote about, they meant what they said. We cannot ignore any of it. It all matters.