2 and 3 John.
2 and 3 John.
§ 285. At one time there was no less doubt about 2 and 3 John than there was concerning Hebrews, James, and 2 Peter. Eusebius, bk. 3, c. 21: “The ancients, as well as the more recent, accept the first Epistle of John without any hesitation, but they speak against the other two.” In the same book, c. 22: “Those that are spoken against, though they are well-known to many, are these: the Epistle attributed to James, etc., and 2 and 3 John, whether they are the work of that evangelist or of someone else with the same name as his.” Book 6, c. 24, from Origen: “John left to us an Epistle with only a few verses. Let the second and third also be added (since they say those are not completely genuine), yet both do not have a hundred verses.” Jerome, Catal. viror. illustr., on John: “There are also two other Epistles of John that are claimed to belong to John the Elder, whose grave still today is at Ephesus. Some think that they are two memoirs of John the Evangelist.” (Eusebius, Hist., bk. 3, c. 36, also decided, in accord with the opinion of Papias, that there are two Johns, namely, the apostle and the elder.) Erasmus, in his commentary: “The authorities are agreed that 1 John is the work of that John whom Jesus loved most and that John the Elder wrote the latter two Epistles, not John the apostle.” In his commentary, Cajetan denies that they are canonical.
§ 286. It can be proved, however, that these Epistles, too, are apostolic and canonical. (1) Their author calls himself 
[“the elder”], which word often signifies ecclesiastical office but here seems rather to indicate his age. But now, it is evident that John reached an age greater than that of the other apostles.
(2) The salutation is fully apostolic: “Grace, mercy, and peace be with you from God our Father and from our Lord Jesus Christ, the Son of the Father, along with truth and concord.”
(3) They agree in statements and words with the first Epistle, as a comparison shows. Bede, in his commentary on 2 John: “Some people think that this and the following Epistle are not the work of the apostle John but of a certain John the Elder, whose tomb can still be seen today in Ephesus. Now, however, the general consensus of the Church holds that the apostle John did write these Epistles because he indeed reveals a great similarity of words and of faith with his first Epistle and also admonishes the heretics with similar zeal.” (Compare 1 John 2:7 with 2 John 5; 1 John 2:23 with 2 John 9; 1 John 3:6 with 3 John 11; 1 John 4:1-3 with 2 John 7; 1 John 5:3 with 2 John 6. Compare also those passages in both Epistles in which he encourages a love that is in truth.)
(4) The ancients cite these Epistles under John’s name and list them with the canonical books: the third Council of Carthage (canon 47), the Council of Laodicea (last canon), Augustine (De doctr. Christ., bk. 2, c. 8). In the Synod of Carthage held under Cyprian, sentence 81 among the decisions of the bishops reads: “The apostle John has stated in his Epistle, saying: ‘If anyone comes to you ….’”
The fact that Papias (in Eusebius) and Jerome attribute these not to the apostle John but to John the Elder proves that these letters belong to the canonical books of the second order. You see, though a few people had doubts about their author while all the rest attribute them to John the apostle, this does not injure their canonical authority. What of the fact that Jerome speaks in accord with the opinions of others rather than his own and says, “They claim that they are the work of John the Elder”? However, when he was about to cite them in Epistle 85 ad Evagrium, he prefaces his remarks as follows: “Let the Gospel trumpet sound, the ‘Son of Thunder’ whom Jesus loved most, who drank the wellsprings of doctrine from the Savior’s breast.” Jerome again, Epistle 103 ad Paulinum: “The apostles James, Peter, John, and Jude published seven Epistles,” etc. From this it appears that Jerome assigned these to John without hesitation.
The second Epistle appears to have been written especially against the wickedness of Basilides and of his adherents, who taught that “Christ was not true man but only a phantom; therefore He did and suffered none of those things He appeared to do and suffer” (Epiphanius, Haeres. 24). Therefore John congratulates “the elect lady,” that is, a noble and outstanding woman who had been converted to Christ, and her sons, because they were holding the true faith concerning Christ Jesus. He encourages them to persevere in it, to adorn it with love and good works, and to watch out for heresies and the architects of heresies with great zeal.
The third Epistle commends Gaius for holding the correct faith regarding Christ and for adorning it with works of love. It encourages him to persevere faithfully in sincerity of faith and holiness of life and to follow the example of neither Diotrephes nor Demetrius in this matter.