A popular joke is told about a person (or a person in a particular profession) with a high opinion of himself or herself. The following joke about doctors was told in 1995:
 
“The difference between God and a doctor is that God doesn’t think he’s a doctor.”
 
“Lawyer” replaced “doctor” in the joke by at least 2005. “Federal judge” was used in the joke by at least 2012.
 
 
Google News Archive
6 February 1995, TimesDaily (Northwest AL), Ann Landers syndicated advice column, pg. 2C, col. 2:
As the saying goes, the difference between God and a doctor is that God doesn’t think he’s a doctor.
     
20 January 2005, Altoona (PA) Mirror, “Attorneys need a sense of humor” by Rowland Nethaway (Cox News Service), pg. A8, col. 5:
Do you know the difference.between God and a lawyer?
 
God doesn’t think he’s a lawyer.
 
Google Books
Don’t Even Think About Telling this Joke to a Lawyer
By Harry Bergen
New York, NY: The Berkley Publishing Group
2007
Pg. ?:
Q. :What’‘s the difference between God and a lawyer?
A. : God doesn’t think he’s an attorney.
 
Twitter
Bev Vincent
‏@BevVincent
The difference between God and a Federal Judge is that God doesn’t think he’s a Federal Judge (anonymous Deputy U.S. Marshal I met today).
1:44 PM - 25 Jul 2012
 
Reuters
Justice Department to federal judges: Get off my lawn
By Alison Frankel AUGUST 29, 2014
Have you heard the old joke about the difference between God and a federal court judge? The punchline is that God doesn’t think he’s a judge – implying, of course, that federal judges have a perhaps inflated perception of their omnipotence.
 
Twitter
Pingere
‏@CJPimentel_
Q: What’s the difference between a lawyer and God?
A: God doesn’t think he’s a lawyer.
11:57 PM - 31 Aug 2014