The Johannine Epistles
There is no shortage of excellent commentaries on the Johannine epistles, both more technical studies on the Greek text and those designed for readers of English only. So let's begin. I'll start with the more substantive works, move to mid-level treatments, and then mention a few that are more collections of sermons on John's letters than commentaries.
The best commentary on these three letters has yet to appear. D. A. Carson is writing on the Johannine epistles for the New International Greek Testament Commentary (Eerdmans). I haven't heard when it will be released, but it will undoubtedly prove to be the best available treatment. Keep an eye open for it and get it!
In the meantime, there are several other extremely helpful treatments of the Greek text that are within the range of the average pastor who reads only English. Just a few months ago Robert W. Yarbrough's, 1-3 John, in the Baker Exegetical Commentary series was released (Baker, 2008, 434 pp.). I've not had the opportunity to look at it in detail, but this will probably prove to be the best treatment of the original text until Carson is published.
Two more, very good and substantial volumes are those by Colin G. Kruse, The Letters of John, in the Pillar series (Eerdmans, 2000, 255 pp.), and Stephen S. Smalley in the Word Biblical Commentary (Word Books, 1984, 386 pp.). On occasion I found Kruse to be too brief. Smalley, in my opinion, is the better of the two. Raymond E. Brown, The Epistles of John, The Anchor Bible (Doubleday, 1982, 812 pp.) is a massive work that often has profound insights. He doesn't believe the author of the Johannine epistles is the author of the fourth gospel, but there's simply too much good material in this volume to neglect it. Donald W. Burdick, The Letters of John the Apostle: An In-Depth Commentary (Moody Press, 1985, 488 pp.), interacts extensively with the Greek text, but if you've got Yarbrough, Smalley, and eventually Carson you may want to bypass it.
There are three mid-level works that every pastor should have in his library. John R. W. Stott, The Epistles of John in The Tyndale New Testament Commentaries (Eerdmans, 1976 [1964], 230 pp.) is my favorite. Be sure you get the Revised edition that was released in 1988 and reprinted in 1996 (234 pp.). Of all the commentaries on the NT that Stott has written, this is his best. Don't even think about teaching through 1 John without reading it carefully.
I. Howard Marshall, The Epistles of John in the New International Commentary on the New Testament (Eerdmans, 1978, 274 pp.) is also very good. As you probably know, Marshall believes a born-again believer can apostatize from the faith and suffer the loss of salvation, and occasionally this negatively affects his exegesis. But it is still worthy of your time. The best treatment of the English text is by Gary M. Burge in the NIV Application series (Zondervan, 1996, 264 pp.). When I taught 1 John I used Burge as the required text. It is theologically insightful and great on contemporary application.
Although they are rather dated, two other treatments are worth consulting. F. F. Bruce, The Epistles of John (Eerdmans, 1970), was one of the first commentaries on John's letters that I read and I always found him helpful. Robert Law, The Tests of Life: A Study of the First Epistle of St. John (T & T Clark, 1914; reprinted by Baker Book House in 1968), reflects the understanding that John is setting forth three "tests" by which one may know if he/she is saved and was highly influential in Stott's approach to the epistles.
There are two collections of sermons on the epistles that will prove helpful to the pastor: James Montgomery Boice, The Epistles of John (Zondervan, 1979), and Martyn Lloyd-Jones, Life in God: Studies in 1 John (Crossway, 1995; five volumes).
If I were planning on preaching through John's letters for the first time, I'd obtain, in order of preference, Carson (when it becomes available), Stott, Yarbrough, Marshall, Smalley, Burge, and perhaps Kruse.
We're almost done. Only Revelation remains.