The three epistles of the apostle John are among the most crucial to study in the New Testament especially in light of the very definition of Christian life is laid out for all to see. Many individuals who plant churches often forget the importance of these epistles especially in light of the main ingredient for planting a church which is love for one another. There are also many theological themes throughout these epistles that make their importance undeniable.
I have unfortunately not collected as many commentaries on these epistles as I would like and to be quite honest I’m certain that there are other fine commentaries available on these letters. My recommendations on a commentary expounding the three epistles are twofold.
The first recommendation is once again from the Pillar New Testament Commentaries edited by D.A. Carson and published by Eerdmans. This volume exegeting the letters of John was written by Colin G. Kruse. This 255 page commentary is a more scholarly volume and filled with exegetical gems that I have found tremendously useful in light of getting through some more difficult portions of the text. Kruse does a good job in laying out the authenticity of the letters, their authorship and a fantastic overview of the purpose of the letters. I also truly appreciated how Kruse spends time giving decently thorough explanation of key themes throughout the letter. For instance when speaking on antichrist, Kruse gives a good overview of that theme throughout the scriptures prior to developing what is said in the letters. This commentary would be a great addition to your library!
My second recommendation is a much more readable commentary. The commentary is not however of all three letters but focusing on 1 John. The title is Life in Christ: Studies in 1 John written by Martyn Lloyd-Jones. It is a collage of a previous five volume set put all into one which runs at about 734 in lenght. The commentary is a compilation of Lloyd-Jones’ sermons on the epistle and has some fantastic practical gems throughout. The writer gives us a very good explanation of the theology he is about to present in each chapter prior to delving into the text. Lloyd-Jones doesn’t hold back in bringing out the sometimes difficult message of each chapter and exhorts the reader to examine themselves in light of the message of the epistles. I feel that this is a fantastic companion to Kruse’s commentary and with both these volumes you are sure to understand the central messages of John’s epistle from a more conservative approach.