God inspired the apostle John to write five books of the New Testament (only Paul wrote more).
Although his name appears nowhere in these epistles, that he is the writer is easily seen by comparing them with the Gospel of John and the book of Revelation. For example, John is the only writer who calls Christ the “Word” (Jn 1:1, 14; 1 Jn 1:1; 5:7; Rev 19:13). The three epistles are written in the same style and the latter two illustrate the doctrine of the first.
The name John corresponds to the Old Testament name Jonah, which means “a dove.” John was the son of Zebedee, a fisherman on the Sea of Galilee, and was the younger brother of James. The brothers worked with their father until Christ called them. They were two of the twelve apostles that Christ chose on earth and sent to Israel with the gospel of the kingdom (Matt 19:28). Peter, James, and John are often referred to as the “inner circle” because Christ seemed to set them apart from the twelve. He is known as the beloved disciple because in his gospel he often referred to himself as the disciple whom Jesus loved.
We have literally no information as to the dates of his writing outside of his own epistles. No one can help us. Neither ancient writers, nor modern critics, can tell us anything beyond what we can read for ourselves in John’s own writings. All else is conjecture. It is commonly believed that all of his writings were written very late in the first century and were the last books to be written (85-95 AD). There is absolutely no biblical proof to support that claim. The gospel of John was written before the destruction of Jerusalem in 70 AD (see Jn 5:2). Tradition says that John was exiled by the Roman emperor to the isle of Patmos in 95 AD, but that is not why John said he was there (Rev 1:9). It is likely that John wrote all of his books during the Acts period.
The first epistle is not addressed to anyone in particular as the other two are (2 Jn 1; 3 Jn 1). John calls his readers “little children” nine times in his first epistle. He wrote to the children of the kingdom (Matt 18:1-14; Jn 13:33). In the transition period of the book of Acts, there were two distinct groups of believers: the kingdom church and the Body of Christ. One group was fading out while the other was fading in.
As late as Acts 15 it is clear that John’s ministry was still to the circumcision (Gal 2:9) and there is no evidence that that ever changed (3 Jn 7; Jam 1:1; 1 Pet 1:1). John’s epistles as well as all the Hebrew epistles have a future application to the Jewish tribulation saints (1 Jn 2:18, 28).
John plainly states some of the reasons that he wrote this first epistle (1 Jn 1:3-4; 2:1, 26; 5:13). He emphasizes knowing the truth (33 times).
Throughout this epistle, John draws stark contrasts:
Light vs. Darkness (1 Jn 1:5)
Righteousness vs. Wickedness (1 Jn 3:10)
Love vs. Hatred (1 Jn 3:14-15)
Truth vs. Error (1 Jn 4:6)
The first sign Christ gave when His disciples asked Him about the sign of His coming and the end of the world was that of false Christs (Matt 24:3-5). The main purpose in this epistle is to exalt the true Christ (Jn 20:30-31) and expose the antichrist (4 times; “wicked one” 4 times). There is an emphasis on believing that Jesus is the Christ, the Son of God who already came in the flesh (1 Jn 1:1-3; 4:1-3). John also writes to show the difference between their followers (1 Jn 3:10). He gives a series of tests (“hereby we know”) to discern the wheat from the tares (Matt 13:36-43). He often uses the expression, “If we say” or “He that saith” (e.g., 1 Jn 1:6, 8, 10; 2:4, 6, 9; 4:20). The little word “if’ is a keyword in this epistle (21 times).
The epistles of Second and Third John are the two shortest books in the Bible. They are similar in style and were obviously written by the same writer who wrote First John. They are appendices to the first epistle. The doctrine of First John is applied to the home (2 John 10) and the local assembly (3 John 9-10). The dispensational setting is the same. It is aimed primarily at the tribulation saints living during the last days of Israel’s prophetic kingdom program. Of course, as with all Scripture, there are applications for us.