Interesting that John the Apostle only introduces himself as “The elder” in his second epistle. He doesn’t even note his name. He starts: “‘The elder to the chosen lady and her children, whom I love in truth'” 2 John 1. He uses the same greeting in his third letter.
Now, if someone is a “Mr.” and also a “Doctor” they usually use the higher title to designate themselves. Apostle is a higher title than elder but John evidently isn’t like most people. He’s not much interested in rank. In this letter he is serving as leader of a local church so elder is plenty good enough for him.
It’s not that titles are bad because they can help us understand how someone functions but those who hold them should do so as lightly as John. I remember a young man I once knew who was a pastor of a small church. He insisted on being called “Pastor” by everyone — even his wife called him that in public.
I thought it strange at the time because the style in churches was becoming more and more informal. But I think this man suffered from some insecurity and needed his title to prop him up.
It’s worth remembering when you look at those with church authority: they may have a different title than you but you both have the same calling: servanthood. On the other hand, if you hold a distinguished rank in the church, follow John’s example and don’t flaunt it.
John suggests the most important thing a few verses after his greeting: “that we love one another.” (Verse 5) Follow that and don’t pull rank.