John writes this gospel for us, so that we believe and continue to believe and know real life in his name. After all, this “faith,” Jude tells us, was delivered to the “saints” (Jude 1:3). So, do not rest on your believing as a past action. Continue to read the gospel story. Reflect. Rehearse. Marvel. Wonder. And believe.

Why does John place the story of “doubting Thomas” at the climax of his gospel? Because John’s whole purpose is to call people to believe in Jesus of Nazareth—his claims about himself, his ministry, his death for sin, and especially his resurrection from the dead—even though they have never seen him.

In fact, out of about 250 times the New Testament uses the verb “believe” (pisteuō), nearly 100 of them occur in John’s gospel alone. And what is even more interesting is that John never uses the noun form, “belief” or “faith” (pistis). For John, belief is always an active idea, a verbal idea.

But John is not merely interested in instilling belief in those who have not yet embraced the good news. He is just as interested in strengthening the belief of those who are already followers of Jesus as well.

We can see this emphasis in the Gospel of John through the way John emphasizes the faith of Jesus’s own disciples at the beginning of the gospel and later toward the end and climax of the gospel. The first person in the Gospel of John who believes is Jesus’s disciple Nathanael.

Nathanael answered him, “Rabbi, you are the Son of God! You are the King of Israel!” Jesus answered him, “Because I said to you, ‘I saw you under the fig tree,’ do you believe? You will see greater things than these” (John 1:49–50).

The next time believing is mentioned it is Jesus’s disciples who believe after the miracle of the water turned to wine.

This, the first of his signs, Jesus did at Cana in Galilee, and manifested his glory. And his disciples believed in him (John 2:11).

Later, in John 2, after Jesus cleanses the temple and declares, “Destroy this temple and in three days I will raise it up” (John 2:19), John forecasts the fact that Jesus’s disciples would later remember that he had said those words and believe:

When therefore he was raised from the dead, his disciples remembered that he had said this, and they believed the Scripture and the word that Jesus had spoken (John 2:22).

After this passage, however, John’s Gospel turns away from the issue of the disciples believing, and gives attention solely to others believing—Nicodemus (John 3), the woman at the well (John 4), the Pharisees (John 5), the 5000 (John 6), the people at the Feast of Tabernacles (John 7), the man born blind (John 9), Martha at Lazarus’s tomb (John 11), to name a few.

But after the people of Israel in general refuse to believe in him (John 12:37), John turns our attention once again to Jesus’s own disciples. Often in the private conversation that Jesus has with his disciples in John 13–16 the subject turns to their believing in him (e.g., John 14:1, 10–12; 16:25–33). Twice Jesus tells his disciples what is about to happen to him in his passion “so that” when it does happen they will remember what he told them and believe (John 13:19; 14:29).