I don’t think you quite understand the place miracles have in the economy of faith. They are not the means by which God buys people into belief. They are, rather, the fruit of trust placed in God.
Consider the parable of the rich man and Lazarus, which Jesus concluded in this way:
Then [the rich man in torment] said [to Abraham, who was in paradise], ‘Then I beg you, father, send him to my father’s house, for I have five brothers, so that he may warn them, lest they too come to this place of torment.’
But Abraham replied, ‘They have Moses and the prophets. Let them listen to them.’
He said, ‘Oh no, father Abraham, but if someone from the dead goes to them, they will repent.’
Then Abraham said, ‘If they will not listen to Moses and the prophets, neither will they be persuaded if someone should rise from the dead.’ (Luke 16:27-31)
Contrast it with the account of the healing of the centurion’s servant:
When he entered Capernaum, a centurion approached him and appealed to him, saying, “Lord, my servant is lying at home paralyzed, suffering dreadfully.”
He said to him, “I will come and cure him.”
The centurion said in reply, “Lord, I am not worthy to have you enter under my roof; only say the word and my servant will be healed. For I too am a person subject to authority, with soldiers subject to me. And I say to one, ‘Go,’ and he goes; and to another, ‘Come here,’ and he comes; and to my slave, ‘Do this,’ and he does it.”
When Jesus heard this, he was amazed and said to those following him, “Amen, I say to you, in no one in Israel have I found such faith. I say to you, many will come from the east and the west, and will recline with Abraham, Isaac, and Jacob at the banquet in the kingdom of heaven, but the children of the kingdom will be driven out into the outer darkness, where there will be wailing and grinding of teeth.” And Jesus said to the centurion, “You may go; as you have believed, let it be done for you.” And at that very hour the servant was healed. (Matt. 8: 5-13)
People don’t magically accept the need to have faith because they see miracles. Miracles, rather, happen to those who choose to accept the faith they are offered, or the faith they ask to be given.