This book began with the Apostle John. It explained the close relationship between John and Jesus, and how he was the one loved by Jesus. John's messages play a key role in the flow of the book. The point is to understand that John's relationship with Jesus means understanding his messages.
We can learn a lot through observing a man's words, especially when that man was so close to Jesus. What we find in both the Gospel and John's letters are descriptions of fellowship and exhortations to believers to pursue fellowship with others. Today's culture needs to change because it is becoming an all-inclusive, it-does-not-matter-what-you-do-or-what-you-have-faith-in -kind of world. This is completely contrary to Jesus' message and the apostles' instruction to the churches. This kind of all-inclusiveness has been foretold in prophecy. It will lead to the introduction of the antichrist. The tumblers are aligning for the end times. It is coming. We must first understand what to look for, know what to do, and whom to trust. This means having an intimate relationship with God. This is why following Jesus faithfully is so crucial.