Epistles of John

The Johannine epistles, the Epistles of John, or the Letters of John are three of the catholic epistles of the New Testament, thought to have been written AD 85–100. The author of these letters is alternatively believed to be John of Patmos, John the Evangelist, John the Apostle, or John the Presbyter.

This epistle unlike the other two is written more as a sermon, one to help strengthen people's faith in Jesus, to help them understand why a being as great as the Son of God would have a mortal life and a mortal's agonizing death.

This Epistle is written as a short letter from the Apostle to an unnamed "elect lady" whom he loves and her children. Within the letter John warns about opening home to false teachers and to always practice truth avoiding secrecy.

The third epistle, also a short letter, is addressed to a man named Gaius and mentioned as "a dear friend". It talks about a man named Diotrephes whom Gaius excommunicated from the church and had gone on to create an anti-missionary sentiment, trying to get the church to stop receiving missionaries. It is believed that the letter was delivered by a third person, Demetrius.

...
Wikipedia