If they will not listen either to Moses or the prophets, they will not convinced even if someone should rise from the dead. (Luke 16:31)
The rich man - who is not given a name, notice - wants Abraham to send Lazarus to warn his brothers that they must change their way of life. Yet, Jesus says, there is no point - they already have all the warning they need. Why should a great miracle make a difference.
There's an important and very broad point being made here, one which we hear several times in the teaching of Jesus and elsewhere in the New Testament, and it is this: all this has been foretold, all this is plainly to be seen in the teaching of Moses and the prophets (what we Christians call 'the Old Testament'), no one should be confused or surprised.
Yet they are. Frequently, Jesus chides his disciples for their failure to understand. After the Crucifixion, the disciples on the road to Emmaus need the prophecies explained to them by the risen Christ. From the day of Pentecost onwards, Peter and other other apostles must explain in their preaching how the coming, suffering and resurrection of Jesus perfectly fulfil what was promised. And St Paul, again and again, argues and explains the old scriptures to show how they point to the new, the Christ, the one who suffered and is risen.
And the point, perhaps is this. People ask for proof. Prove God exists they say. Prove that God is love. Prove that prayer is not a waste of time. Prove that the world is created and didn't just come into existence as a sort of accident or co-incidence. Give us the evidence.
And the proof is already there. We can't show it to them - because they can already see it. We can't convince them of it - because they are already ignoring it. They see, and refuse to believe their own eyes.
The beauty of the world. The wonder of the planets and stars. The miracle of life. The compassion and generosity of humanity. The conviction and self sacrifice of the saints. Its all there. It is before them.
It is not the evidence that is lacking, but the eyes that are closed, and ears that refuse to hear.