What the letter says about its writer
The author introduces himself simply as the elder (2 John 1:1). He writes to a church, or possibly a particular Christian woman and her household, with the warmth of someone they know well. He is delighted that some of her children are walking faithfully, and he expects that he may see them face to face soon (2 John 1:4, 2 John 1:12).
That is all the letter tells us directly about his identity. The title elder can point to an older man, but it was also used for a respected leader among God’s people. Since 2 John never says, “I am John,” the answer involves weighing its connections with other New Testament writings.
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;
Why John the apostle is the traditional answer
Most Christians through history have understood the elder to be John the apostle. John was the son of Zebedee and the brother of James. Jesus called both brothers away from their fishing work to follow him (Matthew 4:21-22). John was also among the three disciples Jesus took with him at significant moments, including the transfiguration and his prayer in Gethsemane (Mark 9:2, Mark 14:33).
The New Testament does not attach John’s name to 2 John itself. Still, John was a well-known eyewitness and church leader, which fits the personal authority and fatherly concern that come through in this brief letter. The traditional conclusion is reasonable, but it should be held with the right kind of humility because the author does not identify himself by name.
The letter sounds like John’s other writings
The strongest biblical reason for connecting 2 John with the apostle John is its close resemblance to 1 John. Both writings bring truth and love together. Both describe obedience as walking in God’s commands. Both warn believers about teachers who deny that Jesus Christ truly came in the flesh (2 John 1:4-7, 1 John 4:2-3).
Those themes also echo John’s Gospel. Jesus teaches that he is the way, the truth, and the life, and he links love for him with keeping his commandments (John 14:6, John 14:15). This does not prove authorship on its own, but the shared language and concerns make a common author a strong possibility.
For many deceivers are entered into the world, who confess not that Jesus Christ is come in the flesh. This is a deceiver and an antichrist.
Could it have been another John?
Some scholars think the elder could have been a different John, perhaps a respected leader serving churches in Asia Minor. That view takes seriously the fact that the letter uses a title rather than a personal name. Faithful Christians can recognise this uncertainty without losing sight of what the letter plainly teaches.
Its central concern is clear. The writer urges believers to remain in Christ’s teaching, love one another, and refuse to support teaching that denies who Jesus is (2 John 1:9-11). So, while John the apostle remains the traditional and most widely accepted author, 2 John calls every reader to focus on the truth about Christ and to live that truth with love.
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.