The name "Cohen" (and variants) comes from a Hebrew word meaning "priest". By Jewish tradition, "Jewishness" is passed through the mother, not the father, so a Jewish man named Cohen who married a non-Jewish woman would have non-Jewish kids with the last name "Cohen". This isn't terribly common, as Jewish men have historically tended to marry predominantly Jewish women, but it's certainly possible for someone to have the last name Cohen and neither self-identify as "Jewish" nor be regarded by Jews (especially Orthodox Jews) as Jewish.
It's also certainly possible for someone to be ethnically Jewish, but not adhere to Judaism as a religion.
Yes. The name Cohen is Jewish to help prove it.
yes
no. he is jewish.
Yes, he is.
There are many famous people named Jack Cohen, and virtually all of them are Jewish.
Cohen, Schwartz, Freid
Cohen, Jovi and variants of these
From what I understand, Cano is the Spanish version of the name Cohen, which is Jewish.
Ben Cohen is not Jewish. His great grandfather was Jewish and married outside of the religion. A Jew is one born of a Jewish mother. Ben was raised Christian. He has mentioned his uncirumcised status.
Well, 'Cohen' is one of many.
A Cohen has no need to go to The Vatican. A Cohen serves a place in Judaism, while The Vatican is the headquarters to the Roman Catholic Church. What need would a Jewish person have at The Vatican?
There are almost no surnames that are uniquely Jewish. If an surname is or was used by a Jewish family, then it is Jewish. If the same surname is or was used by a non-Jewish family, then it is not Jewish. And both can be true at the same time. For example, Cohen is an Irish Catholic surname with no connection to Judaism, yet Cohen is also a Jewish surname related to claims of descent from the Jewish priesthood.