By Doug Potgeter
I met a friend for coffee recently, and we thoroughly enjoyed an edifying conversation about the Bible and theology. At one point in the conversation, we started talking about what a person must believe in order to be born again. My friend mentioned 1 Corinthians 15:1- 4 and proceeded to explain that a person must believe Jesus that died for our sins and was resurrected. After discussing the passage briefly, I brought up the Gospel of John and its many passages in which it is clear that a person is born again when he or she believes that Jesus is the Christ. I was stunned by my friend’s response:
John was writing about the way people were saved in the Old Testament. Now that Jesus has died for our sins and resurrected, we must believe in His work to be born again.
At the time I did not know how to respond to this, but I’ve since come to understand the importance of both John’s purpose and the date the Gospel was written.
The Purpose of John’s Gospel
Someone who is studying resurrection truth will probably use 1 Corinthians 15 at some point. Someone who is studying love will probably turn to 1 Corinthians 13. Someone studying prophecy will more than likely look to the books of Revelation, Ezekiel, or Daniel. The reason is simple: those books and passages deal with those particular topics. And when it comes to the question, “What must a person do to be born again?” we should look to the Gospel of John. Is this because the answer to this question can’t be found elsewhere? No. There are other books of the Bible that contain the message of life (e.g. Acts 16:31; Rom 3:28; Gal 2:16; Eph 2:8-9; 1 Tim 1:16; 1 John 5:1; etc.). However, while other books of the Bible answer this question, there is only one book that was written specifically to answer this question. To put it another way, in the entire canon of Scripture there is only book whose aim and purpose is evangelistic: the Gospel of John. We know this because, in 20:30-31, John clearly stated his purpose for writing:
And truly Jesus did many other signs in the presence of His disciples, which are not written in this book; but these are written that you may believe that Jesus is the Christ, the Son of God, and that believing you may have life in His name.
No other book of the Bible says what John says here, because no other book of the Bible was written for this specific purpose. Therefore, if a person wants to know how to have eternal life, he or she need read no further than the Gospel of John. If further revelation is needed beyond John’s Gospel, then we must concede that John failed to achieve his purpose.
The Date of John’s Gospel
Some object to the sufficiency of John’s Gospel for evangelism by saying that the Gospel’s events occurred before Jesus died on the cross and was resurrected. They, like my friend, contend that the saving message changed after that. Now people must not only believe on Jesus for eternal life, but they must also believe that Jesus died on the cross for their sins and that He was resurrected from the dead. If they do not believe this, they cannot be saved.
The problem with such a position is that, while the events of John’s Gospel did occur before Jesus’ death and resurrection, John did not write his account until years after Jesus ascended. Scholars vary in their opinions of the date of John’s Gospel. Colin Kruse, in his commentary, mentions one scholar who holds to a date in the 60s, before the destruction of Jerusalem in AD 70. Kruse himself holds to a date in the 80s or 90s.1 Even if one holds to an earlier date, it is still true that John wrote his Gospel long after Jesus’ death and resurrection, but if one holds to a later date, the point is strengthened even more.
Since John wrote his Gospel long after Jesus died on the cross, rose from the dead, and ascended, it is reasonable to believe that the saving message did not change and that his Gospel is sufficient to bring someone to Christ. If the saving message changed, why would John have failed to mention such a critical truth? According to John, he and the disciples did not believe a different saving message from the one we believe today. The message is the same, and the critical point to realize is this: if the saving message did change, then John did not succeed in fulfilling his purpose for writing.
George Meisinger makes this very point in the book The Fundamentals for the Twenty-First Century:
John was ‘moved by the Holy Spirit’ to state his purpose, thus we must conclude that he accomplished his goal, recording everything one must do to have eternal life. To suppose otherwise assumes that John either misrepresented, or failed to achieve, his purpose. A proper view of inspiration does not permit such suppositions.2
To say that the saving message changed after the death and resurrection of Christ would imply that John failed in his purpose since he did not say that a person must believe Jesus died on the cross and was resurrected in order to have eternal life. And if we hold that John failed in his purpose, then we undermine the reliability of Scripture. When considered in this light, the sufficiency of John’s Gospel becomes a serious issue.
Conclusion
In the words of John Niemelä,
John’s Gospel was designed for unbelievers. Let us not perpetuate the great omission by taking the one book designed for unbelievers from them. Let us, instead, minister with John’s Gospel to unbelievers and present it to them.3
Based on John’s clear purpose for writing, and the approximate date that he wrote, the most reasonable conclusion is that his Gospel is sufficient for evangelization. Ultimately, while other books of the Bible may be helpful, no other book is needed. John’s Gospel is, indeed, sufficient.
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Doug Potgeter lives in Holland, MI with his wife of ten years, Hannah. He loves to read and spend time with his wife and four boys.
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1 Kruse, Colin G. “Date and Place of Writing.” John: An Introduction and Commentary, InterVarsity Press, USA, Downers Grove, IL, 2017, pp. 16–17.
2 Cited by Shawn Lazar in “Did John Fail?” Faithalone.org, 7 Sept. 2021, https://faithalone.org/blog/did-john-fail/. The Fundamentals of the Twenty-First Century: Examining Crucial Issues of the Christian Faith, edited by Mal Couch (Grand Rapids, MI: Kregel), 2000. Meisinger’s chapter is entitled, “Salvation by Faith Alone.”
3 Niemelä, John. “John’s Gospel: Evangelistic or Not?” Faithalone.org, 1 Mar. 2017, https://faithalone.org/grace-in-focus-articles/johns-gospel-evangelistic-or-not/.