The Book of 2 John does not directly name its author. The tradition from the earliest days of the church states that the author was John the Apostle. There have been various conjectures over the years that another disciple of Christ named John may have been responsible for this letter. However, all the evidence points to the author as John the beloved disciple who also wrote the Gospel of John.
Date of Writing: The Book of 2 John would most likely have been written at about the same time as John's other letters, 1 and 3 John, likely between 85-95 A.D.
Purpose of Writing: 2 John is an urgent plea that the readers of John's letter should show their love for God and His son Jesus by obeying the commandment to love each other and live their lives in obedience to the Scriptures. 2 John is also a strong warning to be on the lookout for deceivers who were going about saying that Christ had not actually risen in the flesh.
Key Verses: 2 John verse 6, "This is love, that we walk according to His commandments. This is the commandment, that as you have heard from the beginning, you should walk in it."
2 John verses 8-9, "Look to yourselves, that we do not lose those things we worked for, but that we may receive a full reward. Whoever transgresses and does not abide in the doctrine of Christ does not have God. He who abides in the doctrine of Christ has both the Father and Son."
Brief Summary: The Book of 2 John is addressed to 'The Elect Lady and her children'. This could either have been a lady of important standing in the community or, which is generally thought much more likely, is a code which in fact refers to the local church and its congregation. In those days when Christians were being persecuted such coded salutations were often used.
2 John is largely concerned with an urgent warning concerning deceivers who were not teaching the exact doctrine of Christ and who maintained that Jesus did not actually rise again in the flesh but only spiritually. John is very anxious that true believers should be aware of these false teachers and have nothing to do with them.
Practical Application: It is extremely important that Christians should check everything concerning Christianity that they see, read and hear with the Scriptures. This cannot be too strongly emphasized as one of the Devil's greatest weapons is deceit. It is very easy to be taken in by a new and exciting doctrine that appears to be based on Scripture, but if examined closely, is in fact a departure from the Word of God. We should be constantly on the alert for this as the Holy Spirit is constantly on the move. If what appears to be happening does not line up explicitly with Scripture, then this is false and not of the Spirit, and we should have nothing to do with it.