So the story goes: how do you know this claim is actually true?
People do get very attached to their chosen causes.
Perhaps his followers wanted to promote the profile of Jesus. Propaganda does happen, so I'd have though it would be important for Christians to exclude this risk before taking the NT claims as being historical fact: to date though it seems they haven't.
The issue here isn't that early Christian weren't sincere even in the face of persecution but whether what they were sincere about was actually true. Bearing in mind we are dealing with post-hoc anecdotal accounts of uncertain provenance where the sources could be biased it could be that some elements (say the empty tomb bit) might be fictional propaganda.
That this story is accepted by some/all Christians without them being able to exclude the risks of mistakes or lies just because it features in their preferred holy book smacks of being a fallacious argument from authority.
The problem is, Gordon, as expressed by your post, that none of it affects you personally...but, I'm afraid it does.
What Jesus was showing you is that there are mechanics, beyond our understanding, that can resurrect each and eveyone of us...and these same mechanics, because Jesus' word can never be altered, also contain the knowledge of everlasting life. By default, that also means he is teaching us a repair process all built around righteousness...or, correct spiritual behaviour.
If we don't believe Jesus...who told us before it happened what would happen, then we have no faith and the alternative to having no faith is to be trapped in the same ether that Jesus snatched the keys to....Oh, I could go on, but I'm afraid I would probably need sign-language.