1689: 1.9: Use Scripture to Interpret Scripture Infallibly
9. The infallible rule for interpreting Scripture is the Scripture itself. Therefore, when there is a question about the true and full meaningc of any part of Scripture (and each passage has only one meaning, not many), it must be understood in light of other passages that speak more clearly.20
202 Peter 1:20, 21; Acts 15:15, 16.
There is nothing wrong with good commentaries. This entire blog is a type of commentary. You listen to a type of commentary when you hear preaching each Lord's Day. So, we shouldn't fear commentaries and should use them enthusiastically. However, the only infallible (means incapable of making a mistake) rule of commentary on the Scripture is the Scripture itself. We can utilize the clearer passages of Scripture to often help shed more light on the more difficult passages. And noticed something the framers of the confession understood: there is only one meaning of a passage. Folks may have different interpretations of Scripture, but the variable lies with the fallible interpreters, not the Scripture. Scripture is clear and there is only one interpretation for its contents.
So what are some ways to use the Scripture as an infallible commentary? First, use your concordance. Concordance Bibles are extremely helpful in this regard. Also, utilize the index in your Bible for topical or word studies. Furthermore, utilize different translations in your study. Reading a verse in different helpful translations can be beneficial to grasping the authorial intent of a text. I would also encourage you to utilize inductive Bible studies like Crossway's Knowing The Bible series. This series can help you invest in particular books of the Bible in an effort to understand its context and theme.
Bottom line: Remember, not only is our Scripture authoritative and sufficient, but it is clear and infallible. Do the hard work of getting to the meaning of each passage.