Defense of the resurrection
When sceptics come to look at the resurrection, it will often seem completely impossible that such a thing could happen. Below are the most commonly used arguments against the resurrection, followed by the Christian defensive response.
Arguments Against the Resurrection, and the Christian Response 
Jesus wasn't dead - just in a coma. 
This seems plausible at first. However, looking at the evidence, it is almost impossible for this to have been the case.
Firstly, the Roman executioners wouldn't have allowed this to happen. The penalty for an executioner not insuring death was death in itself. Would an executioner have been lax, if it had meant a risk to his life?
Secondly, there were four executioners put in charge of each execution. All four would have been executed themselves if the execution wasn't carried out properly. Would all of these men have been neglectful enough to risk their lives?
Further, Pilate was very surprised when he was asked if Jesus could be buried, as it was very early for someone to have died from crucifixion. He sent a man to check whether this was true. The man reported back that it was indeed true. He would've checked with each of the four men, and certainly would have had no reason to lie about the state of Jesus.
There are eyewitness accounts describing Jesus' death, from primary sources, such as John, who is recorded as having been there. It says that when Jesus breathed his final breath, the soldiers shoved a spear through his side, in order to check his death. If he was still alive, water mixed with blood would have come out. However, if he was dead, water and blood would have come out separately, which it is recorded as doing. This is taken as final proof that Jesus was dead.
The disciples stole the body, to fake the resurrection 
This again seems plausible at first glance. It is true that Jesus had told the disciples that he would rise from the dead. When he didn't appear to be doing so, they could have tried to fake a resurrection so as not to look fools.
However, the main flaw with this is the consequences of the resurrection, whether real or fake. The Roman and especially Jewish authorities were very unhappy with the idea that Jesus had been resurrected, for obvious reasons. The Jews were in fact having many of their beliefs threatened by it. They themselves would look fools if it was true. Therefore, they did their best to torture and kill anyone who claimed that Jesus had indeed been resurrected. A fair number of disciples and other believers were caught, and suffered this fate. In fact, Saul, in Acts, was on his way to do just that when he himself was converted.
So if the disciples had faked the resurrection, would they all, on separate occasions, hold to their story under severe torture and eventual death? If they had faked it, it is almost certain that one of them would have cracked under pressure, and rather had his life than had his reputation look good.
The logical conclusion as to why they didn't show it is because they didn't have it. If they didn't have it, then they didn't steal it in the first place.
The Romans stole the body, in order to stop a resurrection 
This argument seems a little flawed from the beginning, since if they did believe Jesus might rise from the dead, and they didn't want him to, what good did they think stealing the body would do?
However, there are other, better arguments against this theory. It is linked to the previous argument a little, in that it rests on the disciples causing disruption by spreading the message around.
The Romans were certainly not very happy when the disciples began to cause chaos by claiming the resurrection of Jesus, as we already know. Now they clearly wanted to stop it, since they were supportive of the Jews' killing of Christians, and themsleves jailed prominent Christians, such as Paul. So since they wanted to stop belief in the resurrection, and they had possession of the body, why did they not produce it?
One simple showing of the dead body for examination would have cleared up the entire affair, in the Romans' favour. There would have been no more danger of losing some of their people, or any more riots, and all that was needed was for them to show the body.
Again, the most logical conclusion to come to from this would be that they didn't in fact have the body at all, and this is why they didn't show it. Because they couldn't. If they didn't have the body, then they didn't steal it.
The appearances of Jesus were hallucinations 
Hallucinations are perceived individually. It is highly unlikely, and therefore not plausible, that an entire group experienced the same hallucination. It becomes even less feasible considering that because the appearance of the resurrected Jesus occurred at different times and places to different people. This also diminishes the applicability of many group psychology theories that might explain an illusion. (though, this does not discount cases of mistaken identity or false claims made by people who didn't know Jesus personally but claimed to have seen him resurrected.)
The appearances of Jesus resurrected was to variety of groups and individuals. This is not cogent with scientific and psychological knowledge of the nature of hallucinations. Therefore, it is very unlikely and nearly statistically impossible that ALL occurrences of the resurrected Jesus are hallucinations.
It wasn't Jesus who was crucified 
The first problem with this is the amount of witnesses. His mother and close friends were all recorded as being present. John, who may have been Jesus's best friend but certainly knew him personally, was one of the people who claimed to have seen the resurrected Jesus. Given how close each person was to Jesus, surely one of them would have noticed if the person who claimed to be Jesus resurrected was not Jesus (even in the case of a person who appeared very similar to Jesus). To emphasize this, scripture provides proof that Jesus talked to John and his mother, two people who knew Jesus very well and personally who wouldn't have been swayed by an impostor posing as the resurrected savior.
The second flaw is that there is no good time for a switchover. He would have to have been Jesus when Judas betrayed him, since Judas knew Jesus and pointed him out by kissing him. From then on, he was constantly under guard: he was taken by a mob, and then transferred to Roman guard. With all the members of the mob, he couldn't have got away, and once transferred to the Romans, he would have had even less chance; they had the strictest and most organised criminal justice system, similar to those seen today.
The logical conclusion from this evidence is that the theory is in fact false. Jesus would have to have been the one who died, not least because people would have noticed if it wasn't the famous man. Throughout the crucifiction process he had no chance to get away.
Grave robbers stole the body 
The aim of grave robbers then and the aim of grave robbers now is the same: profit. The most profitable items in a tomb like Jesus' would have been the cloths saturated with expensive ointments and spices. It is known that the women didn't have time to put them on until they returned after the Sabbath: by this time the body was gone.
So the only thing worth anything when the grave robbers broke in would have been the cloths. And yet even they are recorded as being left. The body was worthless, and very difficult to hide. Grave robbers wouldn't have stolen the body, they would have stolen everything else but the body.
Therefore, one can conclude that grave robbers did not steal the body, since there was simply no reason to.
The women went to the wrong tomb 
Some of the gospels say that it was dark when the women went to the tomb, with others simply saying it was morning. However, in their state of grief, it is possible that they could have gone to the wrong tomb, and if it was dark, it would have made it an even more likely occurrence.
The likelihood ends at this point, though. This theory does not explain a number of things. They found burial cloths in the tomb, and the tomb was also open. It is unlikely that there would be an open tomb with cloths in it around. Also, the womens' sight of the angel, or young man, is unaccounted for.
However, there is one, more weighty point against this theory. The claim the women made when they returned to the disciples was not to be lightly taken. So of course, people would have gone to the tomb to see for themselves that it was empty, and that the women had indeed not gone to the wrong tomb, or been lying.
It would certainly have soon been found out if they were mistaken, as many high profile people were trying to disprove the claims, and if the tomb still contained Jesus, they would have wasted no time in finding and showing his body.
Since no one ever disputed that his tomb was empty, it is therefore extremely unlikely that the women simply went to the wrong tomb.