Did the disciples lie?
It’s hard to argue that the apostles were frauds involved in an elaborate conspiracy. This theory implies that the disciples themselves - or at least part of them - may have taken the body, according to Matthew (Mt. 28:13-15). In Matthew's gospel, this is the first accusation raised. The prior probabilities of such a conspiracy are not very high because the disciples' motives for planning a plot to convince others that Jesus had risen from the dead are difficult to fathom. They knew well enough that such preaching wasn't going to gain them power in society, sexual gratification, wealth or anything else an unscrupulous person would value. Rather preaching the message that Jesus rose from the dead invited persecution and possibly death. It’s for this very reason they fled after Jesus’ crucifixion.
And Peter had denied Jesus. (Mark 14:66-72) This shows us that Peter at the time believed it was in his own best interest to deny any connection to Jesus. Although he seemed to feel tremendous guilt about this, that would hardly motivate him to turn around just a few days later and start spreading a cynical ruse that Jesus had risen from the dead! Peter and the other disciples would also have had to get the women involved in the plot in a short period of time since the women would have been telling their stories at least to other followers of Jesus before Pentecost. Is it plausible that they slipped off to where the various women were staying on the Sabbath, while everyone was still in shock from the crucifixion, and got them to participate in such a hoax within less than 48 hours?
In addition to this, consider how many people would have to be involved in such a ruse, against their own interests, if the Gospels were reliable accounts of what the witnesses claimed. Let’s list them out: For starters, there was the Eleven. Then there were the women. Taking into account the various names in the Gospels, there would be at least five--Mary Magdalene, the other Mary, Salome, Joanna, and at least one more (if we take literally the plural "other women" in Luke 24:11). We now have at least 16 people in two different groups.
Then there would be Clopas and his companion who were on the road to Emmaus. Then there is James the brother of Jesus. There are Matthias and Barsabbas called Justus, named in Acts 1 as fulfilling the requirements of witnesses to the resurrection. Luke 24 also mentions a group of people who were "with the eleven" when Jesus first appeared, which is probably some unspecified greater number of people who also claimed that they saw Jesus risen.
Paul mentions 500 witnesses seeing Jesus at once. Even if one thinks Paul might have been mistaken or somewhat exaggerating in naming such a large group, it seems that others besides the eleven were able to see Jesus on some occasion, presumably in Galilee, separately from the instances when the eleven and others saw him in Jerusalem. Therefore, all of these people must have been involved in the conspiracy, especially those whose names are mentioned or who are known individually. If their names are given, they were presented as specific witnesses to the people whom the disciples were evangelizing, so that they could discuss the matter and describe how they saw Jesus. This is a lot of chances for people to change their minds and decide not to continue with this crazy conspiracy!
Even if you are skeptical of the Gospel accounts, the fact that virtually all scholars - both skeptical and Christian - accept the Easter faith of the disciples is simply due to the extremely low explanatory power of the conspiracy hypothesis. Why should all of those witnesses die or be willing to die for an empirical claim they themselves knew to be false, a claim they fraudulently induced others to believe by committing an act of theft? The fraud theory just doesn’t add up. The disciples were not deceivers.
From a man who knows something about conspiracies
“I know the resurrection is a fact, and Watergate proved it to me. How? Because 12 men testified they had seen Jesus raised from the dead, then they proclaimed that truth for 40 years, never once denying it. Everyone was beaten, tortured, stoned and put in prison. They would not have endured that if it weren't true. Watergate embroiled 12 of the most powerful men in the world and they couldn't keep a lie for three weeks. You're telling me 12 apostles could keep a lie for 40 years? Absolutely impossible.”
- Chuck Colson. Served as Special Counsel to President Richard Nixon from 1969 to 1973. An evangelical leader who founded Prison Fellowship.