I love writing commentaries. I feel as if it is what God made me to do. I have written around twelve of them, ranging from thirty-page overviews to one-thousand-page detailed expositions. I just finished one and will start another in a year or so. I am incredibly thankful that I can spend so much of my time doing what I love.
As much as I like writing commentaries, however, I could hardly justify the work I put into them on that basis alone. I write them because I am convinced that, as flawed as they are, they help God's people understand God's Word and teach and preach it faithfully. The Christian faith, while centered on the Living Word, Jesus Christ, is defined by the written Word, the Scriptures of the Old and New Testaments. God addresses His people through these writings. When we read or hear Scripture, we read or hear God speaking to us. His words, however, come to us in the form of human words. Scripture is the product of what theologians call "concurrence": God and human beings together producing the words of life. Good commentaries help people grapple with God's Word as this fully divine yet fully human product.
On the one hand, therefore, commentaries illuminate the human element of Scripture. The authors of our biblical books wrote in Hebrew, Aramaic, and Greek. We are very blessed to live in an age, and to speak a language that has many good and varied translations. But no translation is able to communicate the full meaning of the original. Translators have a limited number of words that they can use to bring over into English the meaning of the original text. But where translators have to choose a single word or phrase to convey a particular word, a commentator can spend a paragraph or even more explaining the word.
Scripture was also written by people immersed in their own cultures—whether the second-millennium BC ancient Near East of Moses or the first-century Greco-Roman world of the Apostle Paul. Good commentators are familiar with those cultures and can illuminate for readers how the words of Scripture might have been "heard" in those contexts. For instance, commentators might explain that terms such as "good news" and "Savior" were used in Paul's day by Roman emperors, who claimed their policies were "good news" because they brought peace and security, "saving" people from the depredations of bandits and the aggression of other nations. First-century Christians would have "heard" Paul's claim that Jesus alone brings true "good news" and is the "Savior" of the world as a challenge to the emperors' claims.
Good commentaries, however, are not satisfied with explanations of the human dimension of Scripture. To be sure, many scholarly commentaries, some of them written by people who do fully appreciate the divine element of Scripture, can be gold mines of useful information. Ultimately, however, a commentary that fails fully to engage both the divine and the human side of Scripture cannot do justice to Scripture—simply because it is, indeed, a divine-human product. The best commentaries, therefore, move from explanation of the linguistic and historical dimensions of the text to engagement with its theological message. We must understand the ancient context in which the Bible was written to appreciate fully its meaning. But we also have to hear the Bible as a Word from God addressed to His people today. Good commentators, therefore, not only explain the ancient situation of the text but the meaning of the text today. To do this well, the commentator must especially be keen to set any particular text in the context of all of Scripture. We call the Scriptures "the Bible" (singular) because the church sees these sixty-six books as ultimately a single book with God as its author. Commentaries usually explain how a particular verse or paragraph fits within the message of the Bible as a whole.
If the ministry of commentaries is important for the church, how can we best utilize this resource? A quick Google search on "commentaries on John" turns up a bewilderingly long list. Which commentaries should we use? First, use more than one. The very best commentator who has ever written made all kinds of mistakes. Comparing commentaries reveals these errors. Second, use commentaries from different times and cultures. John Chrysostom in the ancient church and John Calvin at the time of the Reformation still have a lot to teach us. And we are blessed to live in a time when more and more commentaries are being written by scholars from different parts of the world. Reading commentaries distant from us in time or culture can help reveal our own biases. Third, read commentaries from different theological traditions. We may not agree with everything such commentators say, but they help us think better about the text and why we believe what we do about it. Finally, use different levels of commentaries. Commentaries vary from massive scholarly tomes that require a lot of dedication to plow through to brief, often superficial reflections on the text. Our tendency is to be content to read the easy ones. But it is good to challenge ourselves sometimes with more detailed commentaries. It pays rich dividends in getting us to think more deeply about Scripture.