The verb ‘to believe’ (pisteuō) occurs nearly 100 times in John’s Gospel. For this reasons, this has sometimes been call ‘the Gospel of belief’.
Sometimes, the verb refers to facts (‘believing that’, as in Jn 9:18; 16:27) or things (Jn 4:50). Often, it refers to a person, where it can mean ‘believe what I say’ (Jn 4:21) or ‘entrust oneself to’ (Jn 5:24).
But the most characteristic Johannine usage is ‘believe in’, where the verb pisteuō is followed by the preposition eis. This construction appears unique to the New Testament, and is particularly prevalent in The Gospel and First Letter of John. It refers to faith in God in Jn 12:44; 14:1, but elsewhere refers to faith in Christ. It is never used of a human object of faith.
Murray Harris explains:
‘it is not simply believing certain facts about Jesus or that all his teaching is true. Belief involves not only recognition and acceptance of the truth, but also, and primarily, total and permanent adherence and allegiance to Jesus as the Truth (John 14:6), a commitment of one’s whole self to the person of Christ as Messiah and Lord forever.’
As Harris affirms, ‘believing that’ leads naturally and properly to ‘believing in’. Even so, there is a world of difference between the two:
|Believing that||Believing in|
|Deals with facts||Deals with a person|
|Involves the mind||Involves the heart|
|Involves recognition of the truth||Involves allegiance to Jesus the truth|
|Can be momentary||Must be continuous|
|Alters nothing||Alters everything|
|Is a natural experience||Is a 'rebirth from above'|
|Is a prerequisite||Is the proper outcome|
‘To believe in Jesus is to come to him (John 6:35), to receive him (Jn 1:12), to drink the water he offers (Jn 4:13–14), to follow him (Jn 8:12), and to love him (Jn 14:21).’
(Navigating Tough Texts, p66f)