"Fishermen"

On Facebook, I responded to an atheist:

If no one knows who wrote the gospels, then they are anonymous. We know they were not written by illiterate fisherman living decades earlier who spoke a different language and couldn't write in any language.

According to traditional authorship, only one of the four gospels was by a "fisherman" (John). Luke was not a fisherman. He was a gentile convert to Christianity/Judaism. Greek was his native language.

Matthew was not a fisherman, but a gov't official. 

Mark was not a fisherman, but a native of highly literate, cosmopolitan Jerusalem. And his family migrated from Greek-speaking Cyprus (Acts 4:36; Col 4:10).

Mark and Luke are written in very simple Greek. 

There's evidence for bilingualism in 1C Palestine.

Moreover, traditional authorship doesn't require John to directly pen his Gospel. He could dictate his Gospel to a scribe. Transcribing oral history. His scribe could be bilingual.