Seeing one rise from the dead can result in belief, if we use the following definitions:
- Belief: accepting that a proposition is more likely than not to be true
- Faith: trusting enough to act
This kind of belief (even if genuine) is not enough; faith is needed.
Greek words in play
- πιστεύω (pisteuó) - to believe, the word employed in John 11:45. Thayer indicates the following usage:
intransitive - to think to be true; to be persuaded of; to credit, place confidence in
transitively - to intrust a thing to one
The same verb is used in James 2:19
Thou believest that there is one God; thou doest well: the devils also believe, and tremble.
When we speak of believing as "thinking to be true", the New Testament is clear that this belief is inadequate. The word, however, overlaps in meaning with and is related to:
- Πίστις (pistis) - faith, belief, trust, confidence, fidelity, faithfulness (source)
This is the word used repeatedly in the New Testament for faith, the belief & confidence sufficient to act. Specifically, the act of repentance (μετανοέω).
- μετανοέω (metanoeó) - to repent, change my mind, change the inner man (particularly with reference to acceptance of the will of God) (source)
Note that it is this change that the rich man in Luke 16 wants to persuade his brothers to pursue. He doesn't simply want his brothers to believe--he wants to persuade them to do something specific:
And he said, Nay, father Abraham: but if one went unto them from the dead, they will repent.
Those who believed after Lazarus was raised from the dead aren't "done". John has already established this reality in chapter 6. After seeing a miracle, believing, and presumably being quite impressed, some of Jesus' followers turned away after He taught them hard things about priorities:
From that time many of his disciples went back, and walked no more with him. (John 6:66)
It wasn't enough for them to be impressed--they needed to be willing to make the kinds of sacrifices Jesus taught in John 6--and they were (to use the definitions from the beginning of the post) willing to believe, but not to proceed to faith & repentance.
Critically, Luke 16:31 employs the word "if". God has given them reason to believe--not just to believe Moses said true things, but to believe enough to repent--and if what God has already given them wasn't enough, the miracle proposed by the rich man won't be enough either.
This form of dialogue is common among those who choose not to believe - "I would believe if I just had more evidence!" The evidence of the Biblical text suggests this simply is not true. God has given evidence (e.g. Job 12:8-10). Asking God questions is encouraged (see Matt. 7:7); but rejecting the evidence God has given or demanding more evidence ad infinitum before repenting is condemned (see Matt. 12:39).
Reasons to believe are given, and if they are faithfully acted upon, more will be given (see also Isaiah 28:9-10).
As noted by Dottard, faith precedes miracles. It may well be that a miracle resulting from someone else's faith catches other people's attention and spawns their own journey of belief. But that new belief will produce no miracles and be no more effective than the belief by the devils in God (James 2:19) or by the rich man's brothers' belief in Moses (Luke 16:31), if it is not followed by faith & repentance.
Far greater than the miracle of giving physical life is the miracle of transforming a human soul for eternal life - this miracle requires more than passive cognitive assent: it requires faith.