Why Was John Written? Understanding the Purpose of the Gospel of John
John's Mission Statement: John 20:30-31
Near the end of his Gospel, the apostle John does something remarkable—he explicitly tells us why he wrote it. In John 20:30-31, he states: "Jesus performed many other signs in the presence of his disciples, which are not recorded in this book. But these are written that you may believe that Jesus is the Messiah, the Son of God, and that by believing you may have life in his name."
These two verses serve as the mission statement for the entire Gospel. They're like an author pulling back the curtain to reveal his purpose, his selection process, and his hoped-for outcome. Understanding John 20:30-31 unlocks the meaning behind every story, miracle, and conversation recorded in the preceding chapters.
The Purpose of the Gospel of John: To Create and Strengthen Faith
John's primary purpose is crystal clear: to generate faith in Jesus as the Christ, the Son of God. Unlike modern biographies that attempt exhaustive coverage, John carefully curated his material. He acknowledges that Jesus did many other miraculous signs that could have been included, but he chose specific accounts that would best accomplish his goal.
This selective approach means every miracle, every teaching, and every encounter in John's Gospel was chosen intentionally. The seven major signs John records—turning water into wine, healing the official's son, healing the paralytic, feeding the five thousand, walking on water, healing the blind man, and raising Lazarus—all point to Jesus' divine identity and authority.
Why Was John Written? Three Key Purposes
1. To Establish Jesus' Identity
John wants readers to understand exactly who Jesus is: the Messiah (Christ) and the Son of God. Throughout his Gospel, John presents evidence for Jesus' divine nature. From the opening verse—"In the beginning was the Word, and the Word was with God, and the Word was God"—John emphasizes Jesus' eternal existence and deity.
The purpose of the Gospel of John centers on this dual identity. Jesus is the long-awaited Messiah prophesied in Hebrew Scriptures and the divine Son of God with authority over creation, death, and salvation. John structures his entire narrative to build this case, presenting witness after witness and sign after sign.
2. To Produce Belief
The phrase "that you may believe" in John 20:31 reveals John's evangelistic intent. Some ancient manuscripts use a verb form suggesting "continue believing," while others suggest "come to believe." This textual variation actually highlights both dimensions of John's purpose—he writes both to help unbelievers come to initial faith and to help existing believers deepen their conviction.
John's Gospel isn't merely informational; it's transformational. He doesn't just want readers to know facts about Jesus—he wants them to place their trust in him. Every chapter invites response. The conversations with Nicodemus, the Samaritan woman, and Thomas all model what it means to move from confusion or doubt to faith.
3. To Offer Life
John 20:31 culminates with the ultimate purpose: "that by believing you may have life in his name." Eternal life is a dominant theme throughout John's Gospel, mentioned dozens of times. John 3:16, perhaps the most famous verse in the Bible, promises that everyone who believes in Jesus will have eternal life.
But for John, eternal life isn't merely about duration—it's about quality and relationship. In John 17:3, Jesus defines eternal life as knowing God the Father and Jesus Christ. The purpose of the Gospel of John extends beyond intellectual assent to a living, transformative relationship with God through Jesus.
How John 20:30-31 Shapes the Entire Gospel
Understanding John 20:30-31 helps us read the rest of the Gospel with proper perspective. Consider how these verses illuminate John's unique approach:
Selectivity over Comprehensiveness: John doesn't attempt to record everything. He's not writing as a modern historian trying to document every detail. Instead, he's carefully selecting material that serves his evangelistic purpose. This explains why John's Gospel differs significantly from Matthew, Mark, and Luke. While they share many common stories, John includes unique material—like the extended discourses in chapters 14-17—that specifically reveal Jesus' identity and relationship with the Father.
Signs over Miracles: John consistently uses the word "signs" rather than simply "miracles" or "wonders." This terminology is deliberate. A sign points beyond itself to something greater. When Jesus turns water into wine or raises Lazarus from death, these aren't just displays of power—they're revelatory signs pointing to his identity and mission. John 20:30-31 confirms this interpretation by calling Jesus' miracles "signs."
Faith as the Central Response: Throughout the Gospel, John presents various responses to Jesus—some believe, some partially believe, some reject him. The climactic confession comes from Thomas, who sees the risen Jesus and declares, "My Lord and my God!" This occurs just verses before John's purpose statement, creating a model of the faith John hopes to inspire in his readers.
Practical Implications of John's Purpose
Understanding why John wrote his Gospel has practical implications for how we read and apply it today:
For Seekers: If you're exploring Christianity, John's Gospel was written specifically for you. It's designed to present Jesus clearly and compellingly, inviting you to examine the evidence and respond in faith. John anticipated your questions and objections, addressing them through the various characters who encounter Jesus.
For Believers: If you already follow Jesus, John's Gospel strengthens and deepens faith. Returning to these passages reminds us who Jesus is and renews our wonder at his love and power. The purpose of the Gospel of John isn't exhausted after initial belief—it continues nourishing mature faith.
For Doubters: Like Thomas, many struggle with doubt. John doesn't condemn questions; instead, he presents evidence and invites investigation. The Gospel acknowledges that belief can be difficult, but it persistently points readers toward faith through testimony and signs.
Conclusion: A Book with Clear Purpose
John 20:30-31 gives us something rare: an ancient author's clear explanation of his work's purpose. John wrote to create and strengthen belief that Jesus is the Messiah and Son of God, so that through believing, readers might experience eternal life in his name.
This clarity of purpose makes John's Gospel one of the most accessible and powerful books in Scripture. Whether you're reading it for the first time or the hundredth, John's stated purpose provides a lens through which to understand every chapter, every sign, and every teaching.
The next time you read John's Gospel, remember these two verses. They're not just a conclusion—they're a key that unlocks the entire book. John carefully selected each account, each conversation, and each miracle with one goal in mind: that you might believe in Jesus and, through believing, have life in his name.
Frequently Asked Questions
What is the main purpose of the Gospel of John?
The main purpose of the Gospel of John is explicitly stated in John 20:31: to lead readers to believe that Jesus is the Messiah, the Son of God, and through that belief, to receive eternal life in his name. John wrote with clear evangelistic intent, selecting specific signs and teachings to prove Jesus' divine identity.
Why was the Gospel of John written differently than the other Gospels?
John wrote his Gospel later than Matthew, Mark, and Luke, with a distinct theological purpose. While the Synoptic Gospels focus on Jesus' ministry in Galilee and parables, John emphasizes Jesus' identity as the divine Son of God through extended theological discourses and unique miracles not found in the other Gospels. His selectivity serves his stated purpose in John 20:30-31.
What does John 20:30-31 tell us about the Gospel?
John 20:30-31 serves as the mission statement for the entire Gospel. It reveals that John intentionally selected specific signs from Jesus' ministry (rather than recording everything) to accomplish one goal: that readers would believe Jesus is the Christ and Son of God, and through believing, receive eternal life.
What are the "signs" mentioned in John 20:30?
The "signs" in John's Gospel are seven major miracles that reveal Jesus' identity and authority: turning water into wine, healing the official's son, healing the paralytic at Bethesda, feeding the five thousand, walking on water, healing the man born blind, and raising Lazarus. Each sign points beyond the miracle itself to who Jesus is.
