John describes himself as ‘the elder’ rather than the apostle. This is certainly not done to diminish his authority but it shows his humility which is the trade mark of the one who did not name himself in his Gospel.
Perhaps another reason why he uses the term ‘elder’ is that an elder moves among the people and at time a difficult exhortation is needed. Perhaps then he uses this term to establish a sympathy with them. John loves them and this is an essential quality for giving any advice. If one who is well known to you has committed a great offence and are to speak to them, make sure you have got anger out of you and have real not just sentimental love for them.
There is a message for us, even in the greeting. We are to love people in the truth, to love people as Christians, as dedicated believers, as promoters of the truth, people who will do whatever they can for the Lord and for the truth.
From the time of Jerome there has been a view that this letter was written to a local church, not to an individual lady. The lady represents the church, and her children are the members of the church. The main factor against this view is that it would mean driving a wedge between the church and the members, something which is unknown in the New Testament. John certainly uses much symbolism, but this view seems unlikely. Taking this view affects the interpretation of the book, for instance in verse 10. Is this literally a house, a home, or is it the church that should not let false preachers teach in it? Are private individuals still permitted to let false teachers come into them? Surely not!