Will we ever know what happens after biological death?

So people who have had NDEs claim that they saw something, but then again, there are even articles that say that NDE visions are just hallucinations that happen due to strong physical pain or something like that, and some article even said that resurrections could rather be some type of unknown bodily process/function/etc. instead of dead people coming back alive and healthy.

So... Will we actually ever know what happens after biological death?