MAMMONISM [ mam–uh-niz-uhm ]
The greedy pursuit of riches.
From the Noun: Mammon:
1. New Testament. riches or material wealth. Matthew 6:24; Luke 16:9,11,13.
2. A personification of riches as an evil spirit or deity.
I always just refer to it as tithing, the collection plate or the building fund.