Well there were apparent eye witnesses who transmitted the events orally. As per Luke's admission, he used various eye witnesses as sources.
Claims are a dime a dozen.
Also loads of Christians died for these beliefs so it is most likely that they honestly believed that Jesus rose from the dead.
Sure. Plenty of people sincerely believe it. So sincerely that they willingly died for it. There are martyrs in pretty much ALL religions. So this is evidence that there were people that sincerely believed. It's not evidence that what they believed is actually correct.
Vikings willingly engaged in fights they couldn't win, not caring if they would die. Their beliefs told them that dieing in battle was honorable and
the way to get into whalhalla.
So them walking unto a battlefield into certain death, is only evidence of them sincerely believing it.
The same goes for the islamic suicide bomber.
Clearly people are very willing to die for their beliefs. So to me, this doesn't register as anything particularly special or out of the ordinary. In fact, looking at the history of martyrdom
accross religions, I'ld even say it's quite common and ordinary.
So with the combination of people dying for the belief, the pretty quick growth of Christianity
The exact same can be said about Islam.
, the fact that there are so many copies of the books which is highly unusual for literature at the time (which shows zeal),
"at the time"?
There were no copies at
that time. The first writings only show up decades and centuries later. The "mass copying" came even later, when the religion already had quite a big following - big enough for many scribes to start doing that work. And this also only shows that people believed and cared enough about those beliefs to do that work. It doesn't demonstrate the beliefs themselves by any means.
Every minority cult at some point suffered persecution, especially in ancient times. These days we call new cults wackjobs. Back then it was blasphemous in light of the "ruling" religions and distancing yourself from the "ruling" cultures instantly puts you at the bottom of society and thus an easy target.
So yes, there could have been fibbing, but emphasis of "could". There could "not" have been fibbing too.
But more then likely, it's the same as all other religions / religious scripture. The quran, the bagavad gita, greek mythology, roman mythology, egyptian mythology, viking lore, scientology, mormonism, etc etc etc.
Clearly, this is something humans did (and still do).
Why would christianity be the odd one of the series that is actually true as opposed to the countless others which you don't believe either?
Also, history isn't set in stone. With almost any proof we have of history, we could say there "could" have been something else happening, but we need proof of such to change our minds. History works on "what is most likely" based on evidence as we might not have all the information.
Yes. And what is most likely, is that christianity and its scriptures is just like all other religions and their scriptures.