To put John’s use of “believe” in perspective, we should realize that this is more than the use of the word in all the other Gospels combined. In fact, John’s Gospel contains well over half of all the instances of pisteuo or “believe” in the whole New Testament.
Clearly, then, “believe” is a key word in understanding John’s Gospel, and we can learn a great deal about the nature of belief and believing by focusing on what John tells us in his account. Three points stand out – John repeatedly shows our faith must be based upon these three aspects of believing.
Based on the Person of Christ
It is not coincidental that the great summary of God’s purpose set out in John 3:16 revolves around belief: “For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life” (John 3:16, emphases added here and below). What we miss, reading this so-often-quoted verse out of context, as is so often done, is John’s continued stress on believing: “Whoever believes in him is not condemned, but whoever does not believe stands condemned already because they have not believed in the name of God’s one and only Son” (John 3:18). Four times in the space of these two verses John hammers home the point that it is only as we believe on the person of Jesus Christ as the Son of God that faith will be rewarded with eternal life.
Throughout his Gospel, John gives many examples of what and why we must believe (2:11; 4:41; 8:24; 10:38; 16:30; etc.), but they are all based upon the person of Jesus Christ, his nature, character, and the work that he accomplished. There is no room in John’s Gospel for any abstract “all you need is love” message. His Gospel is deeply rooted in the necessity of active believing faith in Christ as much as it is in showing the importance of love.
Indeed, the very purpose for the Gospel of John, as the apostle himself tells us near its conclusion, is so that we “ … may believe that Jesus is the Messiah, the Son of God, and that by believing you may have life in his name” (John 20:30-31).
Based on the Work of Belief
Although as Paul affirms, “… the gift of God is eternal life in Christ Jesus our Lord” (Romans 6:23), John’s Gospel paints a complementary picture stressing that although God does give eternal life freely, the gift comes with responsibilities. While Matthew’s Gospel shows Jesus asserting: “Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but only the one who does the will of my Father who is in heaven” (Matthew 7:21), John’s Gospel records Jesus instructing his disciples in the work that relates to faith. When they asked him, ‘What must we do to do the works God requires?’ Jesus answered, ‘The work of God is this: to believe in the one he has sent” (John 6:27-29).
We should not presume that in this statement Jesus is talking only about passively accepting or holding a belief. John’s Gospel stresses that believing is something active that we do, rather than just accept, and that believing is always associated with doing. It is probably not coincidental that like the word “believing,” John also uses the word “doing”(poieō) about one hundred times. This is the larger picture that helps us to correlate what John's Gospel tells us about the work of believing with what the apostle writes about faithful obedience in his epistles (1 John 2:6; 5:3; etc.).
For John, this active believing work is something we do on an ongoing basis – as we see in the way he repeatedly tells us the disciples “believed” as they witnessed Christ’s miracles and teachings (John 2:11; 16:27; etc.), and this leads us to John’s final stress regarding the nature of true believing.
Based on Perseverance
Precisely because true believing is a repeated action on our part, John also stresses that believing must be coupled with perseverance. John gives clear instances of individuals who had believed, but who stopped believing. In John 8, for example, we read: “As he was saying these things, many believed in him. So Jesus said to the Jews who had believed him,'If you abide in my word, you are truly my disciples’” (John 8:30-31).
The importance of ongoing and continuing faith was already stressed by John two chapters earlier when he tells us that previously believing individuals “… turned back and no longer followed him” (John 6:66). This scripture alone shows that believing faith is not something entered into on a one-time basis, but an ongoing action that must be maintained through perseverance.
When John tells us, near the close of his Gospel, that “ … these [things] 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” (John 20:31), the word “believe” in the Greek is literally “be believing” – ongoing persistent believing.
The Three Aspects of Believing
John’s Gospel clearly shows us that true believing is based on the person of Christ, involves active expression on our part, and must be maintained through perseverance. The apostle makes it clear that lack of these three factors led to many not believing or losing the belief they once had. It is in these three ways, however, that John shows we can truly believe, and that through believing we can have life.