Spud,
Or from any other direct witness to the events.
Or from witnesses who would have been close enough to be sure of what they saw, for example by examining the body.
Or from a medical specialist somehow able to ascertain that for example he wasn’t actually witnessing a deep coma.
Or from a witness who actually said, “Jesus was clinically dead” rather than, say, “Jesus looked to me from my vantage point as if he was dead”.
Or from a historian able to eliminate even the possibility of the story changing in the re-telling, especially given its remarkable similarity to resurrection stories from many religious beliefs that preceded it (the syncretism problem).
Or from someone with, say, both DNA technology and the access to use it so as significantly to reduce the risk of mistaken identity.
Or from…
…well you get the idea. So many possible naturalistic explanations, and yet such certainty that the answer was an actual resurrection.
If not for personal faith on the matter, how come?