Introduction: The Purpose of the Gospel of John

Imagine you are on a hike through a beautiful mountain pass, approaching the edge of a cliff that drops a thousand feet to the canyon floor. The only way to continue is to walk across a bridge from one side of the cliff to the other. It’s one thing to say, “I believe the bridge can hold my weight as I walk across this great chasm.” It’s something altogether different to actually start walking across the bridge. The former is a kind of belief based on intellectual adherence to a possible outcome. The latter is placing one’s trust in the bridge. John did not write his Gospel just so we could know facts about Jesus’s life. He wrote his Gospel so we would know facts about who Jesus is and what he was sent to do and in response trust in him completely.

One of the dominant themes of John’s Gospel is our need for life, and it’s always connected to the person and work of Jesus Christ.

In him was life, and that life was the light of men. (1:4; emphasis added)

For God loved the world in this way: He gave his one and only Son, so that everyone who believes in him will not perish but have eternal life. (3:16; emphasis added)

Truly I tell you, anyone who hears my word and believes him who sent me has eternal life and will not come under judgment but has passed from death to life. (5:24; emphasis added)

I am the resurrection and the life. The one who believes in me, even if he dies, will live. Everyone who lives and believes in me will never die. (11:25-26; emphasis added)

I am the way, the truth, and the life. (14:6; emphasis added)

The life we need—spiritual, eternal life, delivered from the judgment of hell—comes through belief in Jesus Christ (20:31). But life does not come to us like a UPS package. It’s not a transaction in which we believe in Jesus, then he hands us our life at the front door and walks away. The life he gives us is life “in him.”

Life in Christ can be illustrated by adoption. When a child is adopted, the significance is not a piece of paper he can place in a file folder. The real meaning of adoption is that he is brought into relationship with a family that is now his own. His existence is tied up with these new family members. They sleep in the same house. They sit and eat meals together. They exchange gifts at Christmas. They cry together when Grandma dies. They pass the flu to one another. Adoption is not an exchange; it’s a new relationship. It’s the beginning of a new life. Life in Christ is not an exchange; it’s being drawn into an eternal relationship with Jesus Christ. He illustrated it for his disciples by comparing their relationship to a vine with branches. The branch doesn’t get a one-time injection of life from the vine. It gets daily nourishment from its connection to the vine, and if something were to sever the branch from the vine, the branch would die. When we truly believe, we truly begin to live.

I was walking through the mall one day when I entered a store and something strange caught my eye. I couldn’t figure out what it was. I stopped and looked around and realized it was something about the mannequin by the window. I walked a little closer, trying to figure out what didn’t fit, when the mannequin looked at me. Then the mannequin blinked. It wasn’t a mannequin; it was a model. The store paid some models to stand in the window and display their clothes.

Models and mannequins are similar in many ways. You find them in the same place. You see them wearing the same clothes. You notice them working the same job. Despite all the similarities, there’s one major, all-important difference. Models are alive; mannequins aren’t. The most expensive mannequin still falls infinitely short of the worst model in one category—life.

The Gospel of John reveals that the most moral, religious, pious person is no more alive than a mannequin in the store window. Though imperfect and struggling with sin, the one who believes on Jesus and commits to following him has been given life. The wrath of God has been removed, the relationship with God reconciled, and eternal life with God guaranteed.