(2 John 1:1) The elder unto the elect lady and her children, whom I love in the truth; and not I only, but also all they that have known the truth;
The apostle John refers to himself as an elder; perhaps he is calling himself "John the elder" to distinguish himself from someone else who might be called "John the younger" or "John the non-apostle". Some consider that someone other than the apostle John wrote this letter but the early church fathers considered he wrote it. This is one of the practical reasons we should study the early church fathers, so we can learn things such as this about which they had first hand knowledge.
John uses an odd title for the recipient of this letter, the "elect lady". If this letter were directed to a woman having a church in her home, perhaps he would not want to use her name (or his own) to protect her from persecution if the letter was intercepted by the Roman authorities. But based on verses 4 and 13, it seems the recipient of this letter is not a person, but a whole community — a bishop and his flock.
John's flock knows the truth as does the flock receiving this letter. Note that truth is the important thing. We should reject things that are not true and we should reject Church leaders who are not teaching truth. Our love for fellow Christians is based on their following the truth. Certainly we should love everyone but that special love Christians have for one another is to be founded on their following the truth. Of course, if you happen to attend a Church in which the others are steeped in sin or if the leaders and others have wacky ideas about foundational doctrines, it makes it hard to consider them as brethren in the Lord. In fact, you may need to shun them even as you attend Church with them.
(2 John 1:2) For the truth's sake, which dwelleth in us, and shall be with us for ever.
(2 John 1:3) Grace be with you, mercy, and peace, from God the Father, and from the Lord Jesus Christ, the Son of the Father, in truth and love.
(2 John 1:4) I rejoiced greatly that I found of thy children walking in truth, as we have received a commandment from the Father.
It is appropriate for John to refer to this congregation as children of their leader. A good Church leader will raise people into God's ways just as a parent raises their children into the ways of life.
(2 John 1:5) And now I beseech thee, lady, not as though I wrote a new commandment unto thee, but that which we had from the beginning, that we love one another.
A strangely-worded verse. John begs this lady, this leader of this local church, that Christians love each other. Perhaps she needs to teach this message stronger to her flock.
If John were using the word "lady" as a code word for something else, he is overdoing it with this verse. I think this letter was indeed written to a woman Church leader.
(2 John 1:6) And this is love, that we walk after his commandments. This is the commandment, That, as ye have heard from the beginning, ye should walk in it.
Notice that love requires works just as faith requires works. None of the intangible aspects of the mind or soul can properly manifest without action. Feeling like you love people, but never doing anything loving is not true love.
One aspect of the commandments of God and of Jesus Christ is to have true doctrine.Some try to de-emphasize the importance of doctrine but John emphasizes it. That said, doctrine should not push away love; both are needed.
(2 John 1:7) For many deceivers are entered into the world, who confess not that Jesus Christ is come in the flesh. This is a [the] deceiver and an [the] antichrist.
The false teaching John was condemning was that Jesus was not really born into this world as a human but was, instead, a phantom or hologram, having no material form. Modern Christian doctrinal disputes seem tame in comparison.
(2 John 1:8) Look to yourselves, that we lose not those things which we have wrought, but that we receive a full reward.
(2 John 1:9) Whosoever transgresseth, and abideth not in the doctrine of Christ, hath not God. He that abideth in the doctrine of Christ, he hath both the Father and the Son.
John again emphasizes doctrine. The correct doctrines about the person and nature of Jesus Christ would obsess the Church for centuries.
(2 John 1:10) If there come any unto you, and bring not this doctrine, receive him not into your house, neither bid him God speed:
They were to not assist heretics who denied the basic facts about the nature of Jesus Christ: that he is deity, the second person of the Trinity, the redeemer of the world. We should thwart the work of people such as these, not help them.
(2 John 1:11) For he that biddeth him God speed is partaker of his evil deeds.
(2 John 1:12) Having many things to write unto you, I would not write with paper and ink: but I trust to come unto you, and speak face to face, that our joy may be full.
These verses should shock adherents of Sola Scriptura; John prefers to share information verbally rather than write it down. Presumably whatever these "many things" are, they are not in the Bible. How can we know about these except by learning what was passed-down to the early church? (and presumably appears in the writings of the early church fathers and the councils).
His communication was verbal, not written. If Sola Scriptura were correct there would be nothing more for him to say: the written word would be sufficient.
(2 John 1:13) The children of thy elect sister greet thee. Amen.
This verse hints that the phrase "elect lady" refers to a pastor (bishop) and his congregation and that the phrase "elect sister" refers to another of these. In hearing that John was composing a letter to this other congregation with which they were familiar, they asked him to send their greetings as well.
Thus, the various local churches are referred to as brothers and sisters, or sisters and sister, each having children.
I suppose it's possible that the woman leading this church has a sister leading another church and that John is currently at that second church writing back to the first church. Or the word "sister" may merely refer to another woman; the leader of the Church John is writing from.
King James Version