by Steven B. Cowan –

“Whatever crawls on it s belly, and whatever walks on [all] fours, whatever has many feet, in respect to every swarming thing that swarms on the earth, you shall not eat them, for they are detestable” (Leviticus 11:42)

“And he saw the sky opened up, and an object like a great sheet coming down, lowered by four corners to the ground, and there were in it all [kinds of] four-footed animals and crawling creatures of the earth and birds of the air . A voice came to him, ‘Get up, Peter, kill and eat!’ But Peter said, ‘By no means, Lord, for I have never eaten anything unholy and unclean.’ Again a voice [came] to him a second time, “What God has cleansed, no [longer] consider unholy.” (Acts 10:11-15)

It is possible that someone might read the two biblical texts listed above and conclude that the Bible contradicts itself. On the one hand, God forbids his people to eat certain types of animals, calling them “unclean” or “detestable.” On the other hand, God tells Peter to eat those very types of animals.

However, Christians believe that the Bible is the Word of God. As such, it cannot err. So, we believe that the Bible cannot really contradict it self. Its teachings must be internally consistent. Yet, there are many apparent contradictions like the ones noted above. There are many biblical texts where the Christian feels that he has to scratch his head and say, “Hmm. I really don’t see how those passages fit together.”

Moreover, when people interpret a given passage of Scripture, it sometimes happens that the interpretation provided is not consistent with what Scripture says elsewhere. For example, does 1 Peter 3:19-20 teach that Jesus literally descended into Hell after his crucifixion and preached to the “spirits” imprisoned there, offering them a post-mortem opportunity for salvation? If so, what are we to make of Jesus’ words to the thief on the cross, “Today you will be with me in paradise” (Luke 23:43) and the teaching of the book of Hebrews that “it is appointed for men to die once and after this comes judgment” (Heb. 9:27)?

Because Scripture does not contradict it self, we need a way to harmonize apparent contradictions so that they can be seen to be consistent. Moreover, we should recognize that we cannot be sure that we have fully understood any passage of Scripture until we have studied what Scripture says elsewhere on the same topic. Yet, once we have compared and contrasted the various texts on a given topic, how do we harmonize them? How do we resolve the apparent contradictions and how do we arrive at a good understanding of what the Bible does actually teach on a subject?

To ask questions like these opens up the issue of systematic theology and its relationship to biblical interpretation. Systematic theology is the discipline that seeks to provide a comprehensive view of what the Bible teaches on any given subject. Believing that the Bible is the inerrant Word of God, theologians are guided in their work by one over-arching principle: Scriptura sui interpres or (in English) “Scripture interprets itself.” The idea is that Scripture it self helps us understand Scripture. One passage of Scripture, in other words, can inform our understanding of other passages so that we do not arrive at the wrong interpretation of any passage or adopt contradictory interpretations. If a person has a hard time understanding some particular biblical text, usually other biblical texts on related topics can help him figure it out. No doubt this is partly what Paul had in mind when he told Timothy to “be diligent to present yourself approved to God as a workman who does not need to be ashamed, accurately handling (literally “dividing”) the word of truth” (2 Tim. 2:15).

Of course, it is one thing to mention the principle that Scripture interprets Scripture. It is another thing to put that principle to practical use. What we need is a set of practical guidelines. It just so happens that there are some standard rules that follow from the belief that the Bible is internally consistent and that it interprets itself. In what follows I will outline and illustrate these guidelines.


  1. Interpret the obscure in light of the clear. Not everything in the Bible is equally clear. Some texts are more clear than others and some texts are downright obscure. Let’s take the passage mentioned above from 1 Peter 3:19-20. This passage is notoriously difficult and numerous interpretations have been offered. Deciding what the text means requires making several exegetical decisions. First, who are the spirits who are in prison? Are they fallen angels? Are they souls of deceased human beings? Second, when did Jesus preach to them? Was it during the time between his crucifixion and resurrection? Was it during the time of Noah? Third, what did he preach? Was it a message of triumph? Was it a call for repentance and faith?

One very popular interpretation of this passage is that Jesus preached a message of repentance and faith to deceased humans during the period between his death and resurrection, offering them a second chance to be saved. Yet, in light of other more clear passages of Scripture, this interpretation is almost certainly false. First of all, as we noted above, Hebrews 9:27 rules out any post-mortem opportunities for salvation. Secondly, it is clear that Jesus’ soul went immediately to heaven after his death. He told the thief on the cross, “Today, you will be with me in paradise,” and he said to his Father, “Into your hands I commend my spirit” (Luke 23:46). So it is highly unlikely that Jesus literally descended into Hell at all, much less to preach a post-mortem gospel sermon. So, applying the rule that the clear is to guide us in interpreting the unclear, we can rule this popular interpretation out. So, what does this text mean? There are a few plausible interpretations, but I will not discuss them here.2 The point to be made, though, is simply that clear texts should guide us in interpreting obscure texts. Following this rule won’t always tell us the correct meaning of a text, but it can at least help us rule out wrong interpretations.

  1.  Interpret the non-didactic in light of the didactic. This principle follows from the first. As Steve Lemke has shown elsewhere in this journal, the Bible contains many different genres or types of literature.3 Some types of literature are better suited than others for different types of communication. For example, if a writer’s primary goal is to evoke emotion or stir the imagination, then poetry or a fictional narrative or parable is usually a good vehicle. On the other hand, if the writer desires primarily to teach or instruct his readers on a particular topic, then a didactic form of writing is often best. By “didactic” I mean a text that provides straight-forward instructional material that is not, for the most part, “dressed up” in figurative, poetic, or narrative language.

Didactic texts (e.g., epistles, legal codes, sermons) are generally clearer than non-didactic texts (e.g., poetry, prophecy, historical narratives). Therefore, if a subject is addressed in Scripture in more than one type of literature, including didactic literature, then the place to start is with the didactic literature. The less clear nondidactic should be understood in the light of the clearer instructional material. This is not to say, of course, that poetic, prophetic, and narrative passages do not teach. Of course they do. The point is that material that is primarily didactic in form and content is usually clearer and less subject to misunderstanding than other types of literature.

To give a simple example, consider Genesis 18. In verse 1, we are told that God appeared to Abraham. From the rest of the chapter, it is clear that Abraham is face to face with someone in human form, having a conversation and a meal with three men who tell him that he and Sarah will have a child and foretelling the destruction of Sodom and Gomorrah. From this historical narrative, someone might conclude that God the Father must have a physical body. Such a conclusion would be mistaken, however, in light of other didactic portions of Scripture. We are told by Jesus, for example, that “God is a spirit” (John 4:24), and the Apostle John makes it clear that “no one has seen God at any time” (John 1:18). We may thus surmise that what Abraham saw was either a pre-incarnate appearance of Christ or simply a physical manifestation of a man that God made to appear and which represented him, but was not literally God himself.

  1. Interpret earlier revelation in light of later revelation. This principle is grounded in the concept of progressive revelation. The idea is that God has revealed himself and his will in the Scriptures progressively. So passages of Scripture that were written later will provide us a clearer and fuller understanding of God and his will than earlier passages. For example, Christians believe that God is triune – that there is one God who exists in three eternal persons. Yet, the Old Testament saints did not have this understanding of God. Though there are Old Testament text s that hint at the doctrine of the trinity Testament text s that hint at the doctrine of the trinity 14), the fullest revelation of God’s triune nature did not come until the time of Christ.

This principle also helps us understand the apparent contradiction discussed at the beginning of this article. Leviticus 11:42 forbids Gods people to eat certain kinds of animals, yet Acts 10:11-15 permits those animals to be eaten. In addressing this problem, the first thing to note is that Peter (whom God tells to eat these animals) and Luke (who wrote Acts) understand that God had previously forbidden this practice. So, it is not as if the author of Acts is contradicting Moses, the author of Leviticus, as if to say that he was wrong. Rather, Luke is recording for us the fact that God’s commands have changed in the New Testament era. In other words, there has been a progress in redemptive history and in Gods revelation. The explanation for the change is that the Old Testament dietary laws, like the sacrificial laws, were not moral precepts that are eternally binding, but ceremonial laws that served a theological purpose in the Old Covenant, but are now obsolete.

W e must guard against an important error at this point, however. The concept of progressive revelation must not be understood in such a way that later revelation is allowed to imply that earlier texts were false or mistaken. Later revelation supplements, clarifies, or (as in the example discussed above) supersedes previous revelation, it does not correct it.

The principle that earlier revelation is interpreted by later revelation is especially important when we are trying to understand the relationship between the Old and New Testament s. There is an old “dittie” that may be helpful to remember: “The New Testament is in the Old concealed; the Old Testament is in the New revealed.” The New Testament – since it provides the fullest and final revelation of God, and since it speaks often about the meaning of the Old Testament – is our primary guide to understanding the Old Testament. If something in the Old Testament is not clear, the New Testament can often help us understand it. If there appears to be a conflict between what the Old Testament says and what the New Testament says, the New Testament has priority.

Old Testament prophecy provides a case in point. Many Christians, especially those who are very fond of “endtime prophecy,” insist on interpreting the Old Testament prophetic books in isolation from the New Testament. Sometimes this leads to mistakes in biblical interpretation. Consider the prophecy in Amos 9:11-12: “’In that day I will raise up the fallen booth of David, and wall up its breaches; I will also raise up its ruins and rebuild it as in the days of old; that they may possess the remnant of Edom and all the nations who are called by My name,’ declares the Lord who does this.” Some Bible commentators take this as a promise that the kingdom of Israel will be literally restored to the earth sometime in the future, perhaps in a future earthly millennium.

This is probably an erroneous interpretation. The reason is that the New Testament interprets this prophecy for us in Acts 15. Notice that the prophecy of Amos connects the restoration of David’s “fallen booth” to Israel’s possession of Edom and the gentile nations. During the Jerusalem Council, when gentiles began to stream into the church after Paul’s first missionary journey, James stands up and makes the following announcement:

“Brethren, listen to me. Simeon has related how God first concerned Himself about taking from among the Gentiles a people for His name. With this the words of the Prophet s agree, just as it is written, ‘After these things I will return, and I will rebuild the tabernacle of David which has fallen, and I will rebuild its ruins, and I will restore it, so that the rest of mankind may seek the Lord, and all the Gentiles who are called by My name.’” (vv. 13-17)

James speaks about the influx of gentiles into the church and declares that this event marks the fulfillment of Amos’ prophecy. This is why it is import ant that we look to the New Testament (later revelation) when seeking to interpret the Old Testament (earlier revelation).


Sometimes following the principles in the previous section will not lead to a clear solution to a problem text. Moreover, when the interpreter is trying to understand what the Bible teaches on a particular topic in which there are many biblical texts that have to be considered, it can be difficult to apply those principles in a straight-forward manner. In such cases, the Bible interpreter or theologian must proceed very much like a scientist who seeks to formulate a hypothesis to explain a large set of observational data about the natural world.

The scientist employs a type of reasoning known as abduction or inference to the best explanation. He assembles the data that he desires to explain and then constructs a theory or hypothesis that he believes explains the data better than any other competing hypothesis. When adjudicating between competing hypotheses to determine which one is best, the scientist appeals to several rational principles such as:4

  • Explanatory power – the best explanation will make the data more probable than competing explanations.
  • Explanatory scope – the best explanation will explain more of the data than competing explanations.
  • Ad hoc-ness – the best explanation will be less ad hoc than competing explanations (i.e. it will require fewer additional assumptions).
  • Coherence with accepted theory – the best explanation will be more consistent with other accepted theories than competing explanations.
  • Simplicity – the best explanation will be simpler than competing explanations.

The Bible interpreter also uses this kind of inference to the best explanation. This becomes evident when we are attempting to discern the Bibles teaching on a large, complex issue such as salvation or the nature of God. For example, there is the perennial debate among Christians over the extent of the atonement. Did Christ die on the cross for every human being or did he die only for the elect? Calvinists take the latter view, Arminians take the former. Some of the biblical data that must be considered in deciding this issue includes:

  • Isaiah 53:4-5 – Surely our griefs He Himself bore, and our sorrows He carried; yet we ourselves esteemed Him stricken, smitten of God, and afflicted. But He was pierced through for our transgressions, He was crushed for our iniquities; the chastening for our well-being [fell] upon Him, and by His scourging we are healed.
  • Mark 10:45 – For even the Son of Man did not come to be served, but to serve, and to give His life a ransom for many.
  • John 10:14-15 – I am the good shepherd, and I know My own and My own know Me, even as the Father knows Me and I know the Father; and I lay down My life for the sheep.
  • Ephesians 5:25 – Husbands, love your wives, just as Christ also loved the church and gave Himself up for her.
  • 1 Timothy 2:3-4 – This is good and accept able in the sight of God our Savior, who desires all men to be saved and to come to the knowledge of the truth.
  • 1 John 2:2 – He Himself is the propitiation for our sins; and not for ours only, but also for [those of] the whole world.

The Bible interpreter will have to think hard about these and other related texts to formulate a hypothesis that understands them in a coherent and consistent way. If there is more than one consistent hypothesis, then an application of the above criteria will allow the interpreter to draw an inference to the best explanation.5


Understanding the Bible is not always easy. This is especially true, as we have seen, when there appear to be contradictory teachings in the Bible. Admittedly, this article has only scratched the surface of this difficult issue. But hopefully we have outlined some guidelines that can help the Bible student faithfully apply the principle that Scripture interprets Scripture.

Steven B. Cowan (Ph.D.) is Associate Director of the Apologetics Resource Center and editor of Areopagus Journal.


1 The following guidelines have been gleaned from several sources, but mostly from R.C. Sproul, Knowing Scripture (Downers Grove: InterVarsity, 1977), 68-79; and Robertson McQuilkin, Understanding and Applying the Bible, rev. ed. (Chicago: Moody, 1992), 232-234.

2 In my opinion, the interpretation that best fits the context and the rest of Scripture is that Jesus preached in the spirit through Noah, during Noah’s own day, to those people who were alive at that time, warning them to repent before the flood destroyed them.  These people, though alive then, are now in the prison of Hell.  A thorough defense of this interpretation, and a discussion of other possibilities, can be found in Wayne Grudem, 1 Peter, Tyndale New Testament Commentaries.

3 Steve W. Lemke, “Good Hermeneutics: Rightly Dividing the Word of God,” XX.

4 These and other criteria related to inference to the best explanation are discussed in Garrett DeWeese and J.P. Moreland, Philosophy Made Slightly Less Difficult (Downers Grove, IL: InterVarsity, 2005), 22.