What do you mean by a miracle? Most modern Christians and atheists would agree on what a miracle is: it is the suspension of the divine clockwork of the universe in favour of an action by God. Most religious people now accept Newton and Galileo, Einstein and even Darwin and suggest that far from contradicting religion, science operates in a different sphere to it. Science studies the regularity of this world, religion the intrusion into this world of another world. We presume to think that such a position is pretty modern- and there is good evidence that it is. For John Cook in the seventeenth century for example rain was not a natural phenomenon but a God given sign that Charles I should follow in the same way as Saul. But such understandings were not the only ones about, and Western religion has oscillated in its understanding of the meaning of a miracle between suggesting a miracle is any marvellous event and suggesting that it is an event which violates the laws of nature.
Consider for example this passage from St Augustine's City of God. It describes the reasons that the people of Rome, after the death of Romulus, beleived he was a God. Augustine suggests that this was a political device, implemented by the senate, to convince the people that the senate should not be treated as traitors for murdering Romulus. He says they were aided in this project of making the King divine by nature: for
For an eclipse of the sun had also occurred and the ignorant multitude, not knowing that this happens according to the determinate laws of the sun's own movement, attributed it to the merits of Romulus. (III 15)
There we have it- a marvellous event is not a miracle, not a divine insertion because it is a natural event created by natures 'determinate laws' rather than by direct divine agency. This is not to say that Augustine did not believe in miracles, he did. But when he describes a miracle he makes it clear that it violated the laws of nature. The eclipse at Christ's death was a miracle as it
did not come about through the natural movement of the heavenly bodies [which] is sufficiently shown by the fact that it took place during the Passover of the Jews. For this festival is held at full moon, whereas eclipses of the sun usually take place at the last quarter of the moon. (III 15)Cook argues that a miracle is an event which signifies something, rain is a sign from God and the whole world can be read for signs of scriptural parallels. Augustine does not see the world as a sign in that sense- it is a sign of the beauty and importance of the divine creator- but every incident cannot be read as a direct signal to human beings of God's intention with regard to a King or a nation. Augustine in that sense is much closer to us than Cook.
The last point is a point that I cannot answer but am interested in- which is whether these two understandings of miracle (miracle as the marvellous and strange event versus miracle as the breaking of a natural law) have coexisted, how they have evolved and changed. The fact that Augustine believed, like Newton, that the natural laws existed and miracles violated them, suggests there is a history here- but for me that history is still unmapped.