In response to happyatheist...

God doesn't require the money, because God is God. The money we provide (I am not a Catholic, but I do tithe) is in thankfulness for God's provision and in understanding that it is God's money in the first place---100%. It should not be mandatory giving, because God loves a cheerful giver. In this way we understand the provision, and we understand that we are merely stewards of someone elses property. I imagine the Catholics have so much because God has provided much. AND... to whom much is given, much is required.