it's fucking wild that people like you seem to think "well you believe SOME things but not OTHERS" is some kind of weird gotcha. of course we do. we have 47 years of evidence of who joe biden is. we all know who he is. america knows who he is. that's like, almost the entirety of why he won the primary in the first place. when things come out that comport neatly with the evidence we have for who joe biden is, it's right to go "hm, yeah, that seems like joe biden, I believe him". when things come out that seem incongruous with biden's history, it's right to go "hm, no, that doesn't seem like joe biden, I don't believe him".
I'm sorry that we're not credulous dipshits that just blindly believe whatever we're told, I guess?