He said "It is Finished"...

:

"So they ran both together: and the other disciple did outrun Peter, and came first to the sepulchre. And he stooping down, and looking in, saw the linen clothes lying; yet went he not in. Then cometh Simon Peter following him, and went into the sepulchre, and seeth the linen clothes lie, And the napkin, that was about his head, not lying with the linen clothes, but wrapped together in a place by itself. Then went in also that other disciple, which came first to the sepulchre, and he saw, and believed."

 I believe that John was momentarily shaken in what he saw. He probably could not believe his eyes. By then Peter had arrived and entered into the sepulchre. He saw where the linen clothes (shroud) lay and also the napkin (“soudarion”/“sudarium”) for Christ's head) lying by itself and not with the shroud. And the grave clothes were both still in a wrapped state. This is what caught the eyes of the Apostle John. And when he went into the sepulchre right after Peter, once again he saw, and then he believed.

John had witnessed the evidence that Jesus had resurrected, that His body was not stolen by friends or foes. Had Jesus' body been stolen, the thieves would not have had the time to unwrap Him.

The evidence of the intact and not unwrapped grave clothes, both the shroud and the "sudarium"  prove that Jesus Christ rose up, from His sleeping position, right though the wrappings, and then passed through the wall of the sepulchre in His resurrected glorified body!  Amen. He was unlike Lazarus who need to be loosed from his wrappings after He raised him from the dead (John 11:44).