Your argument that there certainly was no resurrection rests on the assumption there is no God.
Whereas belief in the resurrection rests on the view that God exists and resurrection is a plausible act for such a being.
Interesting how you attempt to use words to frame these. One is an assumption, the other is a view. Wouldn't be more proper an accurate to say there no no evidence for god nor a resurrection and all evidence in existence points to neither of those things being true, whereas the assumption that both of those things are true has absolutely no backing in evidence whatsoever?
Wouldn't also be exactly as fair to so that the argument that Krampus doesn't exist is also an assumption, just as is it that Jesus didn't poop or have a wife? Or that you aren't made of invisible unicorn teapots orbiting Mars that we simply have no way to detect?
The problem is that once you give an equal weight to "can't prove it isn't true" claims, every claim is just a viable as the next because you've unshackled anything you say from reality.