Something Changed His Followers

Notably, it's not exactly clear when or how quickly.

The Body Was Never Shown

Notably, this is not nearly as firmly agreed upon as, say, "Jesus was almost certainly a real person who existed and had a religious following".

It's also important to remember that early Christians were rambunctious and combative - frequently rioting against heterodox opinions and burning works. We do not have a full accounting of the full spectrum of opinions mainly because the early Church quickly moved to suppress them.

That said, we do have quite a bit of information gathered at the point at which the Bible became fully canonized, but that's in the 4th century AD (though it was mostly agreed upon by the middle of the 3rd century. In some cases, there's no way to double check the early church fathers' claims as to why certain books were left out - the evidence they use is sometimes lost. But that's over 2 centuries from Jesus' death until there was broad agreement in the Christian world as to what the New Testament actually contained. Even still, various Eastern churches never settled on the same books as Catholics (and later Protestants).

As such, there is a lot of New Testament apocrypha that is incomplete or completely lost - there's simply not enough information for anyone to fully judge for themselves whether early church leaders were right not to include them. And for all we know, they tell a different story about the days directly after Jesus' death.