It was not so that he could get out, but so the disciples could get in and see and believe. If they saw that the body was gone, they could know that Jesus was truly risen and was not a phantom when he appeared to them. The bible insists that Jesus was raised bodily, not just spiritually. The choices today are the same as at that first Easter time. Some people are like the Jewish leaders - in their unbelief, they sought to attack the resurrection, and so they made up a story and bribed the guards.
Some people are like the guards.
The guards knew what had really happened, but some of them denied it, out of fear and greed. They preferred the short-lived gain of financial reward, to the everlasting gain of faith in the risen Lord. Perhaps there is someone here today like that. You know deep down that Jesus really did rise from the dead. The evidence is there before your eyes.