So she ran and went to Simon Peter and to the other disciple whom Jesus loved, and told them, "They have taken the Lord from the tomb, and we don't know where they put him." So Peter and the other disciple went out and came to the tomb. They both ran, but the other disciple ran faster than Peter and arrived at the tomb first; he bent down and saw the burial cloths there, but did not go in. When Simon Peter arrived after him, he went into the tomb and saw the burial cloths there, and the cloth that had covered his head, not with the burial cloths but rolled up in a separate place. Then the other disciple also went in, the one who had arrived at the tomb first, and he saw and believed. (Jn 20:2-8 )
The message (news) of the resurrection was first announced to Peter and John. An eye witness communicates first to Peter along with John. The message is that the tomb is empty. Natural conclusion is that the body of Jesus is taken away by someone. Since the news is communicated to the disciples and the disciples also ran to see the empty tomb the author is saying that the disciples were aware of what had happened.
The immediate reaction of the disciples was to run to verify and check. The first one to do that was Peter and then the other disciple also entered to check. They only saw the burial cloths. Empty tomb and the burial cloths were only proofs available. If someone had taken away the body then they would have taken with the cloths. If cloths are left behind the body was not stolen or taken away but something else had taken place.
The other disciple, whom Jesus loved (John) saw and believed. He also saw the tomb empty and he also saw the cloths lying without the body and hence the conclusion was that he was raised from the dead. Belief in the resurrection comes fro the empty tomb and the cloths without the body.
