2 John 1:12-13 (ESV)
Though I have much to write to you, I would rather not use paper and ink. Instead I hope to come to you and talk face to face, so that our joy may be complete.
 The children of your elect sister greet you.
Wouldn’t you love to know what he would have written if he could not come and talk face to face? It can be easy to fanticize. Well, we have to hold that in check. Whatever it was, the Holy Spirit obviously did not want it to be written down. It was for that church.
We have what we have and we can know that it is sufficient for salvation. We can though learn something from this. Pen and ink, phone calls, digital letters on a computer screen are a poor substitute for the presence of a pastor. At times they are necessary and we appreciate that the Apostles wrote what they did. We can appreciate that they wrote even this. Some matters are not to be handled by letter, but face to face, person to person.
“The children of your elect sister greet you. “ This is where I come to the conclusion that John is not talking about individual women. It would be very strange for John to be staying with one woman and passing along information from nameless woman to nameless women, most especially from the children of a nameless woman to another nameless woman. The only good explanation is that he is meaning one congregation to another congregation. And so the terminology of sister congregations begins. We are all family in the church, all adopted by the same God in the election of baptism.