This incident put me in mind of the assessment of divine power described in The Palace of Love (I believe), where various gods were put to the test and Kalzibah came out on top, resulting in a noteworthy increase in his adherents.

Here it looks as if the experiment was interrupted by the custodians of the shrine, however:
http://www.nytimes.com/aponline/2009/11/18/us/AP-US-ODD-Grotto-Hidden-Coins.html