A summary statement of the message of this epistle could be as follows. Abiding in the truth is essential to maintain brotherly love. Let me try to clarify what John was saying in this epistle.
First, he wrote that revealed truth is foundational for the Christian.
John emphasized the importance of revealed truth in five ways.
1. He based his own love on it (v. 1).
2. He based the love of all Christians on it (v. 1).
3. He based his writing of this epistle on it (v. 2).
4. He based the three great Christian graces on it (v. 3).
5. He commended his readers for basing their lives on it (v. 4).
By the truth John meant the teachings of Christ (v. 9). This includes all that Jesus approved as God's revelation (the Old Testament) and all that He taught through His apostles following His ascension (the New Testament; Acts 1:1).
We must keep the importance of God's truth in balance.
On the one hand, it is the only foundation that will adequately support a proper relationship with God and other people. It is the source of our knowledge of God's commandments. As such it is the basis of our relationship with God and other people (v. 8).
On the other hand, it is only the foundation for a proper relationship with God and other people. We must "abide"in that truth. This is not intellectual assent to orthodoxy but a vital relationship in which God controls us. Our walking in the light of God's truth (1 John 1:7) makes this relationship possible.
Second, John wrote that love for others is the fruit of abiding in the truth.
John regarded love for other people as very important for the Christian. His perspective harmonizes with the teachings of the Mosaic Law and Jesus Christ (v. 5).
He also regarded it as essentially obedience to the will of God (v. 6). When we obey God, we do what is best for others. This is what it means to love others. When we abide in the truth, we will love.
Third, John warned against separating love from the truth.
In John's day some people were rejecting the truth but trying to hold on to love.
They claimed to have progressed from elementary truth to advanced truth, but they had really abandoned the truth (vv. 7-9).
John counseled his readers to give the false teachers no encouragement (vv. 10-11). He did not counsel them to withhold love from them.
In our day some people are making the same appeal.
Watch out for appeals to follow teaching that deviates from Scripture. Watch out for appeals that claim a more advanced knowledge of the truth.
We need to learn from this letter how to relate to false teachers. We should not encourage them in their work, but we should reach out to them in love. I once heard a speaker at a conference say, "It doesn't matter too much what we believe as long as we love each other."
John would have said, "It matters very much what we believe because that will determine if we really love each other."Abiding in the truth is essential to maintain brotherly love.