The Urantia Book UB 121:8.10) says 1 John was a covering letter for the Gospel of John, written by Nathan.
Most critics agree that the three epistles have the same author.
There is little doubt that the three letters were written by the apostle John around the turn of the first century, from a province in Asia.
The style, in general, is that of the fourth Gospel.
Slight differences between the epistles and the Gospel of John may be explained by the fact that the epistles were personal letters written by John, while the Gospel of John was really written by Nathan at John’s direction.
The message. “This is the message we have heard from him and proclaim to you, that God is light and in him is no darkness at all.” 1:5.
Certain forgiveness. “If we confess our sins, he is faithful and just, and will forgive our sins and cleanse us from all unrighteousness,” 1:9.
Love not the world. “Do not love the world or the things in the world. If any one loves the world, love for the Father is not in him.” 2:15.
Abiding life. “The world passes away, and the lust of it; but he who does the will of God abides for ever.” 2:17.
Eternal life. “And this is what he has promised us, eternal life.” 2:25.
Sons of God. “See what love the Father has given us, that we should be called the children of God.” 3:1.
Our future. “Beloved, we are God’s children now; it does not yet appear what we shall be, but we know that when he appears we shall be like him for we shall see him as he is.” 3:2.
Brotherly love. “We know that we have passed out of death into life, because we love the brethren.” 3:14.
Testing the spirits. “Do not believe every spirit, but test the spirits to see whether they are of God.” 4:1.
Brotherly love. “Let us love one another; for love is of God.” 4:7.
God is love. “He who does not love does net know God; for God is love.” 4:8. “God is love.” 4:16.
Perfect love. “There is no fear in love, but perfect love casts out fear.” 4:18.
Motivation. “We love because he first loved us.” 4:19.
Obedience. “For this is the love of God, that we keep his commandments.” 5:3.
Victorious faith. “And this is the victory that overcomes the world, our faith.” 5:4.
Eternal life. “God gave us eternal life, and this life is in his Son.” 5:11.
2 JOHN
Orthodoxy. “If any one comes to you and does not bring this doctrine, do not receive him into the house or give him any greeting.” v.10.
3 JOHN
Good health. “Beloved, I pray that all may go well with you and that you may be in health; I know that it is well with your soul.” v.2.