It is often surprising how few seem to know why the New Testament epistles, and we would say the Gospel of John as well, were written. In the main, with the exception of Philemon, they were written to expose false teachers, false teachings, and bad behavior – while also laying down correct doctrine and proper behavior. It is not that the Epistles and the Gospel of John cannot be understood without that information, but knowing that background makes the text far clearer to the readers and far more useful toward the defense of the Christian faith. For example, the Corinthian church had a number of major problems, including false apostles, incest, big egos, and even pandemonium in the gathering of believers. (Paul devoted three chapters to the issues of ego and chaos in chapters 12-14), drunkenness at the celebration of the Lord’s Supper, and more. The reason this epistle was written is quite clear in the text.

When we come to the Gospel of John, the question of why John wrote it is often only partially understood by readers, pastors, and leaders. For example, Got Questions?, for whom we have a great deal of respect, wrote in “When was John written?”:

The Gospel of John teaches that Jesus of Nazareth is God in human flesh and that whoever believes in Him will have eternal life (John 1:1, 14; 3:16). John’s purpose in writing is to persuade sinners to trust in Jesus for salvation (John 20:31).

This is true as far as it goes, but there is perhaps a more important reason for his writing. A little further in, Got Questions? gets closer with:

A clear example appears in the opening verses: “In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning” (John 1:1–2). Scholars suggest that descriptions like this are evidence of years of theological reflection.

We would suggest that John’s gospel stems from more than just his “years of theological reflection,” but rather that John was exposing false teachers and false teachings that had already invaded the church by the 90s A.D. One of the groups John was refuting was the Ebionites. It appears they arose around the mid-First Century and were in existence at least by the time of the Temple’s destruction in 70 A.D. The Ebionites were Jewish and lived by Jewish Law, completely rejecting the teachings of the Apostle Paul. They believed in a version of Jesus that rejected His preexistence before the incarnation. Britannica also notes:

They believed in one God and taught that Jesus was the Messiah and was the true “prophet” mentioned in Deuteronomy 18:15. However, they rejected the Virgin Birth of Jesus, instead holding that he was the natural son of Joseph and Mary. The Ebionites believed Jesus became the Messiah because he obeyed the Jewish Law.¹Britannica; Ebionite

“Who Were the Ebionites, and How Did Their Beliefs Clash with Biblical Christianity?” explains:

At the heart of Ebionite theology was a denial of the incarnation. They taught that Jesus was a mere man, born naturally of Joseph and Mary, and that he was chosen by God at his baptism to fulfill a prophetic role. They rejected the virgin birth (contradicting Luke 1:35 and Matthew 1:18–25) and denied the preexistence of Christ (John 1:1–14; Colossians 1:15–17). This made them early proponents of adoptionism, the false idea that Jesus became the “Son of God” by merit or divine favor, not by eternal nature.

So, although the Ebionites believed in “a” Jesus, it wasn’t “the” Jesus through whom one can be saved. John tells us his purpose for writing this book was:

so that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name. (John 20:31)

John was writing a First Century apologetic on Who Jesus is!  It wasn’t just any Jesus these people were to put their trust in, but a specific One, the one who is the Son of God and has the power to give them life.

The second group John exposed taught Docetism, the heretical idea that Jesus wasn’t a physical being but only seemed physical:

Docetism, derived from the Greek word dokein, meaning “to seem,” was a heretical teaching from the late first century which asserted that Jesus Christ only appeared to be human but was not truly so. Adherents of Docetism claimed that Christ’s humanity was a mere illusion, and His suffering and death were not real but only seemed to occur. This doctrine directly challenges the biblical teaching of the full humanity of Jesus, which is a foundational element of the Christian faith. As the apostle John warned in 1 John 4:2, “Every spirit that confesses that Jesus Christ has come in the flesh is from God.”²“What is Docetism, and How Does It Contradict Biblical Christology?,” Edward D. Andrews, Christian Publishing House

In the first fourteen verses of his gospel, John presents his thesis, and throughout the rest of the book, he uses various incidents, confrontations, and statements in the life of Jesus to support his claims. In John 1:1-3, he begins with the Ebionites’ denial of the preexistence of the Son:

In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through him, and without him was not any thing made that was made.

John points the reader to first words in the Book of Genesis and asserts that the Word already existed when creation occurred. Not only did the Word preexist creation, but the Word was with God and, in fact, is God! In addition, the Word created everything that exists and therefore cannot Himself be a creature. While John is refuting these false teachers that had already crept into the church in his day, he is also providing the defense for refuting groups like the Jehovah’s Witnesses today, who hold similar heretical views.

Once John exposes the false teaching of the Ebionites, he turns his attention (in John 1:14) to the Docetists who denied the physicality of the Son.

And the Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth.

The Word, John clearly states, took on physicality. “The Word became flesh.” Yes, Ebionites, the Word preexisted creation, and yes, Docetists, the Word was physical, not a phantasm!

Throughout the rest of his book, John shows up the heresies of these false teachers by giving examples in the life and ministry of the Messiah. In John 2:18, he records a challenge by the Jewish leaders (who are most often in this writing just referred to as “the Jews”):

So the Jews said to him, “What sign do you show us for doing these things?”

This encounter took place after Jesus cleansed the temple (John 2:13-17), and these leaders were, shall we say, less than happy about His actions. His response is one that exposes both heretical groups:

Jesus answered them, “Destroy this temple, and in three days I will raise it up.” The Jews then said, “It has taken forty-six years to build this temple, and will you raise it up in three days?” But he was speaking about the temple of his body. (John 2:19-21)

He would raise the temple, which John points out was the “temple of His physical body,” not the building in Jerusalem. John is pointing out that in order to raise His own body, Jesus would have had to be more than just a human, but indeed had continued existence even while He was separated from His body and also, that He was the very One who would raise it! To the Docetists, John is making the case that Jesus was physical – and that when He raised His body, it would be physical! To the Ebionites, John was showing that He was exercising the power of God over life and death.

We could show this wonderful pattern of John’s apologetical expose’ all the way through the Book of John, but we will jump ahead to chapter 20. At this point, the death, burial, and resurrection had occurred just as prophesied. Jesus had presented Himself to the disciples, but Thomas wasn’t there, and the disciples told Thomas what had happened. You might recall his response:

“Unless I see in his hands the mark of the nails and place my finger into the mark of the nails, and place my hand into his side, I will never believe.” (John 20:25)

Jesus then engaged in a sort of “challenge accepted.” He would give Thomas the opportunity to put his finger and hand into the holes in the Lord’s hand and side. So, eight days later, Jesus arrived again in their midst, and gave Thomas the opportunity to touch His physical body and check out the wounds. (John 20:26-28) Thomas may have been skeptical, but his skepticism was so very helpful for the rest of us through the ages, to understand and show that the Bible teaches that Jesus was raised in the very same body he was crucified in. No “spiritual resurrection” here, thank you very much!

In our more youthful days, we engaged, along with other apologetic men and women, with active JWs on a JW forum on AOL. The Internet was a fairly new medium at that point. One of the JWs in that forum was a fairly formidable opponent, in that he could find a way to twist scriptures in a sufficient enough fashion to convince JWs on the forum that he was their knight in shining armor, which caused some apologetically minded Christians to refrain from engaging him there. Of course, over time, we who did engage with him became his “friend” of sorts in private texts that went back and forth in a less defensive manner. No one was watching. The one verse I (Joy) can recall leaving him without even his usual twisty bravado was this verse in John 20. He did not even pretend he had an answer, but admitted this was a “hard one to answer.” Of course, he never would have admitted that in the public forum itself, but we were more or less “friends” by then, after several years. But I have never forgotten his admission, and I still pray for that man from long ago, as well as some other “combatants” from those days of yore.

The Apostle then wraps up his apologetic by recording the purpose of the book:

Now Jesus did many other signs in the presence of the disciples, which are not written in this book; but these are written so that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name. (John 20:30-31)

But which Jesus did John insist they (and we, all these centuries later) believe in? Not the Ebionite version or the version of Docetism, but the One that preexisted all of creation and indeed created all of creation. The One who incarnated as a man to live a perfect life and die a terrible death in our place, raise His physical body, and thus defeat death for us. By believing in this One, we have salvation! John, like the other apostles in their own books, refuted serious heresy and clearly laid down sound doctrine about the Savior and the necessity of placing our trust in Him alone and not trusting in our own feeble and useless efforts to “earn” salvation. No human being has ever been good enough or done enough good works to earn a place in heaven. Our salvation must be by faith alone.

The Apostle John picks these themes up again in his epistles 2nd & 3rd John:

The apostle John was particularly concerned with this heresy, as he emphasized the reality of Christ’s incarnation. In 1 John 4:2-3, he writes, “By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God, and every spirit that does not confess Jesus is not from God.” Then, in 2 John 7, John also warned against those who deny “that Jesus Christ has come in the flesh,” clearly opposing Docetic beliefs.³“What is Docetism, and How Does It Contradict Biblical Christology?,” Edward D. Andrews, Christian Publishing House

Knowing the background behind why certain books were written and why certain things were included gives us a fuller context for understanding them. John was showing the church how to answer these false teachers and teachings. The various false teachers we deal with today may not be carrying all of the exact same heresies into the church with them, but they are close enough that John and the other apostles have equipped us with a very good defense for the faith if read in context. Perhaps that is why Paul wrote 2 Timothy 2:15, which we will quote from the KJV translation we first memorized from:

Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth.Ω

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