I want to begin a brief but entirely new series of studies of 1 John. And to begin with I want to look at the purpose for which 1 John was written. It is possible to read a book without understanding the purpose for which it was written. Indeed, much reading is done on this level by many persons. But it is not possible to study a book without dealing with this primary question.
This is true of any document. If an article has been written to argue a legal point, no one will turn to it to find religious inspiration. It was just not written for that purpose. Again, if a verse was composed as love poetry, no one turns to it for its narrative value, as one would to a novel. Instead, one turns to it to discover and in some sense experience the emotions that love poetry conveys. It is the same in approaching the Bible. Each book has a purpose, in some cases a distinct purpose. So it is of value, in fact essential, to determine what that purpose is in the case of the book to be studied. In the case of John’s first letter this is also extremely rewarding. For the problems which John faced in his day are quite strikingly the problems of our own time, and the objectives which he sets before himself are objectives which Christians today must also have if they are to grow in grace and to continue to present the authentic message of the Word of God to their contemporaries.
So why was 1 John written? The first answer to this question (and the clearest) is that which John himself gives toward the end of his letter. It is expressed in chapter 5, verse 13. “These things have I written unto you that believe on the name of the Son of God, that ye may know that you have eternal life, and that ye may believe on the name of the Son of God.” John’s first purpose is to bring Christians to the absolute assurance of their salvation.
The nature of this purpose is seen in sharp relief when it is contrasted with the equally explicit statement of John’s purpose in writing his Gospel. John says that there were many other things that Jesus did which he has not recorded but that “these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name” (John 20:31). Here those to whom he is writing are not yet Christians (though we are not to suppose by this that Christians did not use his Gospel), and his purpose is to lead these to faith. In the first epistle his purpose is to lead those who already believe to a deeper understanding of the faith and to confidence in that which they already possess.
What caused John to write in this fashion, elaborating upon what other biblical writers seem almost to assume? As we read the letter we discover that it was a situation in the church to which he was writing, produced by the fact that shortly before this some of the more talented or intellectual members had withdrawn from the fellowship to found a new one. They claimed that their movement represented an improvement on what had been taught before (2:19 ff.). Naturally many of the other members of the church were confused. Were the new teachers right? Was the old teaching to be abandoned? Where did the truth lie? Had they been Christians all along or were their former beliefs only a preparation for this higher and only authentic form of Christianity? In short, how could one know when he was truly a child of God? How could a believer know when he was born again?
To these questions John replies, first, with the categorical statement that a Christian can know and should know that he has eternal life and, second, with three practical tests by which an individual can settle the matter.
