What is the analogy of Scripture?
We’ve all probably heard the phrase, “Scripture interprets Scripture.” When we say “Scripture interprets Scripture,” we are talking about the analogy of Scripture. Second Timothy 2:15 says, “Be diligent to present yourself approved to God, a worker who does not need to be ashamed, rightly dividing the word of truth.”
In order to “rightly divide the Word of truth” we need to have recourse to God. God must teach us how to rightly divide His Word. Apart from a divine standard of interpretation, we will always foist our culturally conditioned assumptions and prejudices into the text. We need an ultimate Interpreter, and this ultimate Interpreter is God Himself through His Word.
The Second London Confession 1.9 reads, “The infallible rule of interpretation of Scripture is the Scripture itself; and therefore when there is a question about the true and full sense of any Scripture (which is not manifold, but one), it must be searched by other places that speak more clearly. (2 Peter 1:20, 21; Acts 15:15, 16)”
Clearer texts further our understanding of more ambiguous or less clear texts. So, when it comes to less clear texts, e.g. Rev. 20:4-10 (millennium), and 1 Cor. 7:14 (holy children), we need the rest of the Bible—the clearer texts therein—to better understand them.
Richard Muller, in his Dictionary of Latin and Greek Theological Terms (one of the most important books of our century), defines the analogy of Scripture (analogia Scripturae) in this way, “[it is] the interpretation of unclear, difficult, or ambiguous passages of Scripture by comparison with a collation or gathering, of clear and unambiguous passages or “places” (loci) that refer to the same teaching or event.”
 Richard Muller, Dictionary of Latin and Greek Theological Terms, (Grand Rapids, MI: Baker Academic, 2017), 25.