The Christian gospel is based squarely on a miracle. It was the miracle of the resurrection of Christ that started it going, and that same miracle is its central message. Indeed, the basic qualification of a Christian apostle was to be an eyewitness of the resurrection, and for centuries Christians have greeted each other at Easter time with the confident words, "Christ is risen! He is risen indeed!"

C.S. Lewis expresses the situation precisely: "The first fact in the history of Christendom is a number of people who say they have seen the Resurrection. If they had died without making anyone else believe this 'gospel', no Gospels would ever have been written." According to the early Christians, then, without the resurrection there simply is no Christian message. Paul writes: "If Christ has not been raised, our preaching is useless and so is your faith."

The question is: can we make sense of this claim in a scientifically literate society? For the Christian gospel conflicts with the widely held notion that belief in miracles in general, and New Testament miracles in particular, arose in a primitive, pre-scientific culture where people were ignorant of the laws of nature, and readily accepted miracle stories. In the oft-quoted words of David Hume (1711-76):

"A miracle is a violation of the laws of nature; and as a firm and unalterable experience has established these laws, the proof against a miracle, from the very nature of the fact, is as entire as any argument from experience as can be imagined ... It is no miracle that a man, seemingly in good health, should die on a sudden: because such a kind of death, though more unusual than any other, has yet been frequently observed to happen. But it is a miracle that a dead man should come to life; because that has never been observed, in any age or country. There must, therefore, be a uniform experience against every miraculous event; otherwise the event would not merit that appellation."

Hume denies the miraculous, because miracle would go against the uniform laws of nature. And yet elsewhere he denies the uniformity of nature. He famously argues that, just because the sun has been observed to rise in the morning for thousands of years, it does not mean that we can be sure that it will rise tomorrow. This is an example of the Problem of Induction: on the basis of past experience you cannot predict the future, says Hume. But if that were true, let us see what follows.

Suppose Hume is right, and no dead man has ever risen up from the grave through the whole of earth's history so far; by his own argument he still cannot be sure that a dead man will not rise up tomorrow. That being so, he cannot rule out miracle. What has become now of Hume's insistence on the laws of nature, and its uniformity? He has destroyed the very basis on which he tries to deny the possibility of miracles.

In any case, if according to Hume we can infer no regularities, it would be impossible even to speak of laws of nature, let alone the uniformity of nature with respect to those laws. And if nature is not uniform, then using the uniformity of nature as an argument against miracles is simply absurd.

I find it astonishing that, in spite of this fundamental inconsistency, Hume's argument has been responsible to a large extent for the widespread view that we have a straightforward choice between mutually exclusive alternatives: either we believe in miracles, or we believe in the scientific understanding of the laws of nature; but not both. For instance, Richard Dawkins claims:

"The nineteenth century is the last time when it was possible for an educated person to admit to believing in miracles like the virgin birth without embarrassment. When pressed, many educated Christians are too loyal to deny the virgin birth and the resurrection. But it embarrasses them because their rational minds know that it is absurd, so they would much rather not be asked."

Not so. For there are eminent, scientists, like Professor William Phillips (Physics Nobel Prizewinner, 1998), Professor Sir John Polkinghorne FRS (Quantum Physicist, Cambridge) and, in the United States, the current Director of the National Institute of Health and former Director of the Human Genome Project, Francis Collins (to name just three) who, though well aware of Hume's argument, nevertheless publicly, and without either embarrassment or any sense of irrationality or absurdity, affirm their belief in the resurrection of Jesus Christ, which they regard as the supreme evidence for the truth of the Christian worldview.

Such scientists do not feel threatened by Hume because his idea that miracles are "violations" of the laws of nature, is fallacious, as C.S. Lewis illustrated:

"If this week I put a thousand pounds in the drawer of my desk, add two thousand next week and another thousand the week thereafter, the laws of arithmetic allow me to predict that the next time I come to my drawer, I shall find four thousand pounds. But suppose when I next open the drawer, I find only one thousand pounds, what shall I conclude? That the laws of arithmetic have been broken? Certainly not! I might more reasonably conclude that some thief has broken the laws of the State and stolen three thousand pounds out of my drawer. One thing it would be ludicrous to claim is that the laws of arithmetic make it impossible to believe in the existence of such a thief or the possibility of his intervention. On the contrary, it is the normal workings of those laws that have exposed the existence and activity of the thief."

The analogy also helps point out that the scientific use of the word "law" is not the same as the legal use, where we often think of a law as constraining someone's actions. There is no sense in which the laws of arithmetic constrain or pressurise the thief in our story! Newton's Law of Gravitation tells me that if I drop an apple it will fall towards the centre of the earth. But that law does not prevent someone intervening, and catching the apple as it descends. In other words, the law predicts what will happen, provided there is no change in the conditions under which the experiment is conducted.

Thus, from the theistic perspective, the laws of nature predict what is bound to happen if God does not intervene; though, of course, it is no act of theft, if the Creator intervenes in his own creation. It is incorrect to argue that the laws of nature make it impossible for us to believe in the existence of God and the possibility of his intervention in the universe. That would be like claiming that an understanding of the laws of the internal combustion engine makes it impossible to believe that the designer of a motor-car, or one of his mechanics, could or would intervene and remove the cylinder head. Of course they could intervene. Moreover, this intervention would not destroy those laws. The very same laws, that explained why the engine worked with the cylinder head on, would now explain why it does not work with the head removed.

It is, therefore, inaccurate and misleading to say with Hume that miracles "violate" the laws of nature. We could, of course, say that it is a law of nature that human beings do not rise again from the dead by some natural mechanism. But Christians do not claim that Christ rose from the dead by such a mechanism. They claim that he rose from the dead by supernatural power. By themselves, the laws of nature cannot rule out that possibility.

When a miracle takes place, it is the laws of nature that alert us to the fact that it is a miracle. It is important to grasp that Christians do not deny the laws of nature, as Hume implies they do. It is an essential part of the Christian position to believe in the laws of nature as descriptions of those regularities and cause-effect relationships built into the universe by its Creator and according to which it normally operates. If we did not know them, we should never recognise a miracle if we saw one.

And that also puts paid to Hume's idea that accounts of miracles "are observed chiefly to abound among ignorant and barbarous nations." You cannot recognise an abnormal event, if you do not know what is normal. This was recognised long ago.

The brilliant ancient historian Luke, a doctor trained in the medical science of his day, begins his biography of Christ by raising this very matter. He tells the story of a man, Zechariah, and of his wife, Elizabeth, who for many years had prayed for a son because she was barren. When, in his old age, an angel appeared to him and told him that his former prayers were about to be answered and that his wife would conceive and bear a son, he very politely but firmly refused to believe it. The reason he gave was that he was now old and his wife's body decrepit. For him and his wife to have a child at this stage would run counter to all that he knew of the laws of nature. The interesting thing about him is this: he was no atheist; he was a priest who believed in God, in the existence of angels, and in the value of prayer. But if the promised fulfillment of his prayer was going to involve a reversal of the laws of nature, he was not prepared to believe it.

Luke here makes it obvious that the early Christians were not a credulous bunch, unaware of the laws of nature, and therefore prepared to believe any miraculous story, however absurd. They felt the difficulty in believing the story of such a miracle, just like anyone would today. If in the end they believed, it was because they were forced to by the sheer weight of the direct evidence presented to them, not through their ignorance of nature's laws.

To suppose, then, that Christianity was born in a pre-scientific, credulous and ignorant world is simply false to the facts. The ancient world knew the law of nature as well as we do, that dead bodies do not get up out of graves. Christianity won its way by dint of the sheer weight of evidence that one man had actually risen from the dead.

Most of our evidence comes from the New Testament and it may surprise many that, in comparison with many other ancient works of literature, the New Testament is by far the best-attested document from the ancient world. Sir Frederic Kenyon, who was Director of the British Museum and a leading authority on ancient manuscripts, wrote:

"The number of manuscripts of the New Testament, of early translations from it, and of quotations from it in the oldest writers of the Church is so large that it is practically certain that the true reading of every doubtful passage is preserved in some one or other of these ancient authorities. This can be said of no other ancient book in the world."

The empty tomb

It is the constant and unvarying testimony of the Gospels that the tomb was found to be empty when the Christian women came early in the morning of the first day of the week, to complete the task of encasing the body of Jesus in spices. And when the apostles went to investigate the women's report, they likewise found the tomb empty.

If the tomb had not been empty, the authorities would have had no difficulty in producing the body of Jesus, demonstrating conclusively that no resurrection had happened. If they had had the slightest evidence that the tomb was empty because the disciples had removed the body, they had the authority and the forces to hunt down the disciples, arrest them and charge them with tomb-robbing, which at the time was a very serious offence.

Tomb-robbers would not have taken the corpse, and left the valuable linen and spices. And even if, for some unfathomable reason, they had wanted only the corpse, they would have had no reason whatever for wrapping all the cloths round again as if they were still round a body, except, perhaps, to give the impression that the tomb had not been disturbed. But if they wanted to give that impression, they would surely have done better to roll the stone back into its place! But here we meet another matter: how could any tomb-robber have removed the stone when the guard was there? The noise would have been considerable. The rolled-away stone was a complete give-away that the tomb had been disturbed.

But it was the way in which the grave-cloths were lying that convinced St. John of a miracle. So, could someone have taken the body and rewound the cloths deliberately to give the impression that a miracle had happened? But who could this have been? It was morally impossible for the followers of Christ to have done it. It was also psychologically impossible, since they were not expecting a resurrection. And it was practically impossible, because of the guards. It would be absurd to think of the authorities doing anything remotely suggestive of a resurrection. After all, it was they who had ensured that the tomb was guarded, to avoid anything like that!

The early Christians did not simply assert that the tomb was empty. Far more important for them was the fact that subsequently they had met the risen Christ, intermittently over a period of forty days. According to Paul's list in 1 Corinthians 15, there were originally well over five hundred people who at different times saw the risen Christ during that period.

But it is not only the number of eyewitnesses who actually saw the risen Christ that is significant. It is also the widely divergent character of those eyewitnesses, and the different places and situations in which Christ appeared to them. For instance, some were in a group of eleven in a room, one was by herself in a garden, a group of fishermen were by the sea, two were travelling along a road, others on a mountain. It is this variety of character and place that refutes the so-called hallucination theories.

Psychological medicine itself witnesses against these explanations. Hallucinations usually occur to people of a certain temperament, with a vivid imagination. But Matthew was a hard-headed, shrewd tax-collector; Peter and some of the others, tough fishermen; Thomas, a born sceptic; and so on. They were not the sort of people one normally associates with susceptibility to hallucinations.

Again, hallucinations tend to be of expected events. But none of the disciples was expecting to meet Jesus again. The expectation of Jesus's resurrection was not in their minds at all. Instead, there was fear, doubt and uncertainty - exactly the wrong psychological preconditions for a hallucination.

Hallucinations usually recur over a relatively long period, either increasing or decreasing. But the appearances of Christ occurred frequently, over a period of forty days, and then abruptly ceased. Hallucinations, moreover, do not occur to groups and yet Paul claims 500 people saw Jesus at once.

In any case, hallucination theories are severely limited in their explanatory scope: they only attempt to explain the appearances. They clearly do not account for the empty tomb - no matter how many hallucinations the disciples had, they could never have preached the resurrection in Jerusalem, if the nearby tomb had not been empty.

To anyone who knows anything about the ancient laws regarding legal testimony, it is very striking that the first reports mentioned in the Gospels of appearances of the Risen Christ were made by women. In first-century Jewish culture, women were not normally considered to be competent witnesses. At that time, therefore, anyone who wanted to invent a resurrection story would never have thought of commencing it in this way. The only value of including such a story would be if it were both true and easy to verify. Its very inclusion, therefore, is a clear mark of historical authenticity.

The evidence of the empty tomb, the character of the witnesses, the explosion of Christianity out of Judaism and the testimony of millions today are inexplicable without the resurrection. As Holmes said to Watson: "How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?"

John Lennox is Professor of Mathematics at Oxford University, a Fellow in Mathematics and the Philosophy of Science at Green Templeton College, Oxford and an Honorary Fellow at Wycliffe Hall, Oxford. He is the author of several books, including Gunning for God: Why the New Atheists are Missing the Target and God's Undertaker: Has Science Buried God?