What was the Apostle John aiming for when he wrote the gospel which bears his name? The apostle tells us in chapter 20, verse 31, that everything he has written was so that we might believe, and that by believing you may have life in his [Jesus’] name. Having considered the content of the belief (that the Messiah, the Son of God, is Jesus), we should ask what is the belief itself? What does it mean to believe in Jesus?
Reading through John’s gospel, one thing clear: he is not seeking a mere intellectual assent. Saying, oh yes, that’s what I think! is not the sort of belief he is driving for.
John 2:23-25, Now when he was in Jerusalem at the Passover Feast, many believed in his name when they saw the signs that he was doing. But Jesus on his part did not entrust himself to them, because he knew all people and needed no one to bear witness about man, for he himself knew what was in man.
Jesus looks at the belief of those who have seen him do signs, and yet he doesn’t entrust himself to them. Implied in the text is that they are duplicitous, wishy-washy, and that this faith of theirs is short-lived. (cf., John 6:25-29)
The faith Jesus seeks (and thus for which John aims) isn’t a temporary faith, a faith based only on what it can see. It’s a faith that sees what God has done in the past, and subsequently trusts him for the present and the future. This sort of faith is summarized by trusting in Jesus, receiving him for all that he is, and following him. The New City Catechism, in answer to question 30, “What is faith in Jesus Christ?”, answers this way:
Faith in Jesus Christ is acknowledging the truth of everything that God has revealed in his Word, trusting in him, and also receiving and resting on him alone for salvation as he is offered to us in the gospel.
This strikes the same note as John’s emphasis on abiding.
John 8:31-32, So Jesus said to the Jews who had believed him, “If you abide in my word, you are truly my disciples, and you will know the truth, and the truth will set you free.
Believing in Jesus certainly must begin with an intellectual assent. But it cannot stay there. It leads to a life characterized by abiding in Christ and his word. Trusting and following him wherever he leads. You see, all those who have been genuinely born from above (see chapter 3) have the Spirit dwelling in them. And having come to know the Truth (Jesus, see 14:6) and being filled with his Spirit, they are transferred from death to life. Darkness to light. They receive the greatest gift they could ever receive: adoption into the family of God (1:12). John wants you to trust Jesus in this consistent, lasting way. Do you?