Millions of people have traced their ancestry to the Islamic prophet Mohammed. None can say the same of Jesus. Even Joeseph Smith has living descendents. No one claims to be related to Jesus though.
No body. No DNA. No remains. No tomb. No descendents = Didn't exist.
Spartacus, No body, no DNA, no tomb, no descendents = Didn't exist...except he did.
Sebastian the First of Portugal. No body, no DNA, no tomb, no descendents = Didn't exist...except he did.
Glenn Miller. No body, no DNA, no tomb, no descendents (his children were adopted) = Didn't exist...except he did.
Anyone who died childless and was cremated, lost at sea, went missing, burned up in a fire, all the children who have been abducted and never recovered...none of them ever existed by your definition.
I'm beginning to believe that in your haste to post something anti-Christian, you failed to think this all the way through.