Lyric discussion by sakebox 

Cover art for The Highwayman lyrics by Johnny Cash

Although most (if not all) of these men are devout Christians, the song is about reincarnation. I also believe that they are all singing as different incarnations of the same soul.

You'll notice that Willy Nelson was a highwayman, and in the last stanza Cash says that he "could be a highwayman again." Either they're different highwaymen----which is unlikely, or they're the same person.