In the nine verses studies in this passage of Scripture, a great deal of theological truth has been unpacked. Of course, there commentaries that focuses on slightly different aspects of this passage. There is general agreement among scholars as to the meaning intended by John in this epistle. The lack of controversy with regard to authorship has certainly proven beneficial for the author. Still, this passage studies offers rich theological detail for study.
Living out the few remaining years of his life, John writes all five of the books attributed to him likely from about A.D 85 to A.D. 100. 1 John is perhaps written with the intention of being circulated among a number of churches in the Roman province of Asia. The closing passage of this letter reinforces themes John previously developed in the letter such as the confidence believers should have in their salvation and promise of eternal life, the fact that God hears an answers prayers made in His will, and God provides believers with an understanding of the nature of the world and His word.
Two particular areas where further study would be quite beneficial would be verses 16-17 where the Apostle discusses intercessory prayer and the sin being committed by a so-called brother. John suggests earlier that a true Christian can fall into habitual sin (cf. 3:9) yet John refers to a brother who commits a sin that leads to death. Can a true Christian commit such sin? Another area of interest for further study is the question of who John intends to refer to in verse 20. Does being in him who is true refer to be in Christ or being in God the Father? There are scholars who argue for both positions.
Perhaps the best way to gain a better understanding of 1 John is in studying the Gospel that bears his name. 1 John follows many of the themes in his Gospel and the two works are certainly complementary of one another. In fact, before undertaking a study of the book of Revelation, it may well be best to study all four of the other books attributed to John. His writing style is unlike the other biblical authors and yet in simple, modest language he manages to communicate some of the most difficult theology to be found in Scripture. As for the current study, it has been a pure joy to undertake.