But, if someone walked out of a tomb, that would be a sufficient basis for believing what that person had to say.
Just because THE BIBLE says that someone walked out of a tomb (presumably a dead someone), does not mean it is proof of THE BIBLE being correct about that or anything else. THE BIBLE cannot corroborate THE BIBLE.
Even WTS demands TWO WITNESSES. (Mattew's Bible account and Luke's Bible account are NOT two witnesses.)
When a child falls through the ice while skating and is finally recovered 30 minutes later and yet is revived, that makes the National News! ABC NBC CNN FOX AP Etc. and it is included in more than one study on the subject and debated in Medical Journals.
Even the writings of Josephus, which is said to make two references to the existence of Jesus of Nazareth, was unaware of the man being crucified or of any record or even rumors of his rising from the dead. (WOW!) Perhaps that kind of event just wasn't newsworthy back then, despite that numerous sources that do note the births and deaths and reigns of the Cesars and other world rulers.
Just call me Thomas.