A fun riddle. How does a preacher know when agnostics are listening?

[PlainPat]

It's up to you to tell me. I don't reverse or add in details section. Return the favor.

 

[techilikey]

Everyone is agnostic because nobody knows.

 

[Someone who cares]

Obviously, it is unknown.

 

[Sldgman]

When they do not know the answer to the questions.

 

[Cygnus Alpha]

Their little eyes light up when the ice cream truck goes past.