You are called to interpret the Word of God just as you interpret other forms of communication in the most obvious, the most natural sense. As it has been well said, to interpret the Bible literally is to interpret the Bible as literature. Thus, when a biblical author uses a symbol or an allegory, we do violence to his intentions if we interpret him literally.
Consider, for example, the Lord’s words in John 2:19: “Destroy this temple,” said Jesus, “and I will raise it again in three days.” The Jews understood Jesus in a wooden, literal fashion. They thought He was saying that the temple, which had taken forty-six years to build, could be destroyed in three days, and rebuilt again in that period of time. Jesus, however, spoke figuratively, as John explained the temple He had spoken of was the temple of His body. Likewise, when the apostle John describes Satan as a dragon, or variously as an ancient serpent (Rev. 20:2), we’d be seriously mistaken to suppose that he intends to communicate that Satan is literally a smoke-spouting snake!
My point is simply this: a literalistic method of interpretation does as much violence to the text as does a spiritualized interpretation that empties the text of objective meaning. So to avoid either extreme, you as a believer need to adeptly employ the literal principle of biblical interpretation. You need to pay careful attention to what is called form, or genre, figurative language, and even the kind of fantasy imagery that the apostle John uses in the Book of Revelation. Now when we talk about Satan being a dragon, dragons are obviously the stuff of mythology, not the stuff of theology.
So you need to exercise your mind to grasp what the author is driving at. Metaphors, when we use them, even in common parlance, are used in ways that have significant meaning. They have sharp teeth. It doesn’t mean that when you use metaphorical language that you’re not pointing to something concrete, or something substantive; it means that you have to use your mind to get what the author is driving at. This is certainly true with biblical forms or figures of speech. As a believer you need to learn to read the Bible for all its worth.