Is it a religion or is it a culture?

I am Jewish and know many Jewish Buddhists Jewish ✝️Tians. Jewish individuals such as this still keep the culture but don’t do the religion, still go on USY stuff and other things like that. But then I’ve seen people who say that these same people are not Jewish anymore and can’t even speak Hebrew or Yiddish or Landino or do anything else remotely Jewish. I’m not trying to muddy the water or anything but I just want to know if it is or not. There was a Jewish ✝️tian in here before and someone said he/she didn’t even deserve to eat matzo ball soup anymore, and then there was another and they said you’re still Jewish. So if you are Jewish and you don’t proselytize to others your religion and keep your own beliefs private, are you still Jewish? How much of a culture really is it?

I’m not a troll and I’m just wondering

Edit: I’m not a Christian troll. I just have a very good culturally Jewish friend who practices Catholicism but still loves Jewish culture and she’s such a nice lady. Not a proselytizer