Each gospel tells the story somewhat differently. In Mark's Gospel, when the women arrived, the stone was already moved and there was a young man in the tomb. If this were our only source, we could simply assume that this young man was one of a group who had removed the body of Jesus, and he had remained behind for some reason. So, in Mark's Gospel, the absence of the body of Jesus is easily explained, with or without faith.
Matthew's Gospel attempts to pre-empt this by having a guard placed on the tomb because the authorities, with surprising foreknowledge, expected the disciples to claim that Jesus was risen from the dead. However, none of the other gospel authors knew of this guard, and, regardless of how Jesus left the tomb, we can expect that the guard would surely have arrested the young man that Mark's Gospel talks about. It would be reasonable to believe that Matthew's guard was a clever addition to the story in order to make the Resurrection more plausible.
Having pointed out that each of the gospels accounts contradicts the others in considerable detail, and that Matthew's guard is an apparent elaboration, it is useful to point out that scholars say that Matthew's Gospel and Luke's Gospel are based on Mark's Gospel, with additional sayings from the hypothetical 'Q' document. Others say that John's Gospel was inspired by Luke's Gospel, with some material taken direct from
Mark. This informs us that, if the authors of
Matthew,
Luke and
John had to rely on
Mark, then they really knew nothing about the burial and resurrection of Jesus. Where they differ from
Mark, they are elaborating the only story known to the authors.
The answer to the question comes down to whether Jesus really disappeared from the tomb, or whether Mark also engaged in some creative writing. If Jesus really disappeared from the tomb, we have already seen how the young man could have been a sentinel for a group of grave-robbers. If the other gospel writers can be described as having elaborated the story they received from Mark, then it is equally credible that Mark, in turn, elaborated an earlier text by adding an account of the missing body. In its original form (before the later addition of the "Long Ending", verses 16:9-20),
Mark never mentioned any appearances of the risen Jesus.