Together with the letters of James, Peter and Jude, the three letters of John belong to the 'general epistles'. It has already been indicated in previous paragraphs that this name was invented by people and in fact does not do justice to these letters. The content shows that these letters are not just written to Christians in general, but to readers with a Jewish / Israelite background.
As in the Gospel of John, we do not find the name of the writer in this and the other letters of John. The only Bible book that mentions John's name is the book of Revelation (chap. 1:1). Incidentally, John was one of the "pillars" of the church in Jerusalem (Gal. 2:9).
It is generally assumed (from tradition) that the Epistles of John were written at the end of the first century AD, from Ephesus. However, there is no evidence for this at all. From a substantive point of view, it is more likely that the letters were written during the Acts period. John clearly writes from the background of the imminent return of the Lord; all kinds of characteristics of that lead time emerge in the letter. For example, he writes about the (spirit of the) antichrist (chap. 2:18 and 22 and 4:3) and says that it is "the last hour" (ch. 2:18). Moreover, in chapter 2:28 and 3:2 it is about the appearing of Christ and the expectation of it is also heard. Moreover, chapter 2:28 speaks of the (future) coming of the Lord; literally it says: in His presence (parousia). We find this expression literally in 1 Corinthians 15:23 and 2 Corinthians 7:7.
Because the 'normal' letterhead is missing, we cannot find the addressees in addition to the name of the writer. From John's apostleship we can in any case assume that we are dealing with Jewish / Israelite readers. He generally refers to them as (his) babes (eg 2:2, 12, 18, 28 and 3:18) and lovers (eg 2:7 and 4:1 and 7).
B. 2:18-29 Antichrist.
C. 3:1-24 Love.
B. 4:1-6 Antichrist.
C. 4:7-21 Love.
A. 4:7-21 Christ.
We already wrote something about the background of this letter under 'Writer, origin and destination'. This background largely determines the purpose and content of the letter. In the run-up to the presence (parousia) of the Lord Jesus Christ, John clearly points out the necessity of openly bearing the witness at that time. In addition, the believers cannot just 'walk the wrong way', as far as faith is concerned. Of course that is not necessary in our time, but in that future time these things will come to light much more. Where we can often keep things hidden, that is not possible. You are either for or against God. You are either born of Him (and then you do not sin) or you are not of Him (and so you do sin); compare chapter 3:5 and 9. In verse 8 of that chapter John writes: "...he that committeth sin is of the devil...". It is the solemn time described by the Lord Jesus in the sermon on the last things, in which He spoke of false christs (Matt. 24:24). A time of choices and a practical revelation of faith in which it will become clear to whom the believers will belong: Christ or the antichrist.
The 'black and white' that characterizes the letters of Peter and, to a greater extent, those of James, can also be clearly tasted here; that is, the way in which this is formulated. John points out to the believers that only confessing the faith in deed counts (chap. 3:18); only then does love really manifest itself.
All in all, the first letter of John is an encouraging letter that urges the "little ones" and "beloved" to testify for the truth, to have a blameless walk, and to show God's unconditional love, as proofs of true faith. Actions rather than words!
“And this is the record: God hath given us eternal life, and this life is in his Son. He that hath the Son hath life; he that hath not the Son of God hath not life . . . we know, that the Son of God came, and hath given us understanding, to know the true: and we are in the true, in his Son Jesus Christ: this is the true God, and eternal life” (chap. 5:11, 12 and 20).