Those Pharisees just would not leave Jesus alone would they? The Chief Priest and the Pharisees are bothering poor Pontius Pilate again. Of course, at this point, Jesus had died on the Cross and been placed in the tomb. The priests had heard of Jesus saying He would rise from the dead in three days, and wanted to make sure that did not happen; so, they were there to ask Pilate to put a guard on the tomb.
One could easily suspect that neither Pilate nor the priests were actually concerned that the disciples were planning to steal the body; perhaps they had heard enough and seen enough that they knew was really going to happen.
Friends, the Resurrection is the most significant event in human history; by it the work of Jesus was finished as he arose and conquered death so that one day we might also conquer it. It has been said that when Jesus died on the Cross, that he wrote the check and that when He arose, the check cleared. Without the Resurrection, our faith is just a meaningless, empty shell based on simply another dead prophet.
The Resurrection is not only necessary, but it is one of the most well documented and supported by evidence of all the events in the Bible. Now, as then, it is also one of the most attacked events contained in it. Without the Resurrection, we have nothing. Is it any wonder the scoffers attack it so vigorously?