The practice of biblical theology is concerned not just with the trees but with the forest—the Big Picture. Biblical-theological instincts want to read parts in light of the whole, and that means seeing specific texts within the larger context of Scripture’s progressive revelation.
Let’s take an example from Genesis 3. According to Genesis 3:1, a serpent came to Eve and began to tempt her to eat from the forbidden tree. Now this serpent isn’t named in the chapter at all. Genesis 3 has twenty-four verses, and throughout them the figure is only called the “serpent.” But who is this oppositional figure? The chapter doesn’t give more information. In fact, the serpent isn’t mentioned throughout the rest of Genesis. Moreover, the serpent isn’t mentioned in the rest of the Pentateuch (Genesis through Deuteronomy).
Yet the interpretive instinct of Bible readers is to understand the tempter in Genesis 3 as Satan. Is that because the serpent is named thus in the chapter? No. The reason Bible readers make that identification is because of later biblical revelation.
In the book of Job, for instance, the being known as Satan wants to destroy Job’s integrity and turn him against the Lord. That agenda sounds like the same goal the serpent of Genesis 3 had for Adam and Eve. In the Gospel of Matthew, Satan comes to Jesus in the wilderness to tempt him by twisting God’s words—a strategy familiar to us because of Genesis 3.
Now notice the language of Revelation 12, which speaks of “the dragon” (Rev 12:3, 7). The text refers to this “dragon” as “that ancient serpent, who is called the devil and Satan, the deceiver of the whole world” (12:9). The interchangeability of these terms is significant. Satan is the devil, the devil is the dragon, the dragon is the deceiver, and the deceiver is that ancient serpent. Revelation 20 provides even further confirmation. The “dragon” is called “that ancient serpent, who is the devil and Satan” (Rev 20:2).
The textual evidence shows that later biblical authors have clarified the identity of the serpent in Genesis 3. I can confidently say that the tempter in Genesis 3 is Satan because the Bible is coherent and consists of progressive revelation. The book of Job, the Gospel of Matthew, and the book of Revelation can all help me understand more about who is tempting Eve in Genesis 3.
Christians confess the unity of Scripture. The Old and New Testaments are not an anthology of disconnected stories. The Bible is coherent because the Divine Author has inspired the biblical writings. If you don’t think that later biblical texts shed light on the identity of the tempter in Genesis 3, what do you think that says about your view of Scripture?
Your reading practice is downstream from your reading presuppositions. And doing good biblical theology assumes Scripture’s unity and coherence. This Christian presupposition establishes the important practice of reading widely.
By “reading widely,” I mean the practice of reading across the canonical revelation of Scripture in order to let later texts shine light on earlier passages. If I want to know who the tempter is in Genesis 3, I need to read widely. I need to leave that chapter—and even the book of Genesis—to see what later Scripture has to say. And evidence from later biblical authors tells me that the ancient serpent in Genesis 3 is the one known as Satan or the devil.
If I’m trying to understand something in the Old Testament, then reading widely—or reading across the Testaments—means I’m allowing more authoritative and inspired texts to illuminate the passage I’m studying. Reading widely increases clarity, enriches meaning, and demonstrates the coherence of the Word of God.