charity wrote: Probably active LDS adults donate more than many other church members donate because of tithing. Except that in the Catholic, Anglican, and other major denominations the wealthier people pay fairly substantial amounts, but don't call it tithing.
Lots of other churches use the term "tithing," and believe in the principle of a "tithe," even if they don't execute it exactly the same way as is done inside the LDS world.
If you Google "tithing," you'll find lots of non-LDS examples, including this one, which seems to echo a lot of your own sentiments about "giving to God":
Here an essential point of tithing must be noted: God does not ask us to tithe because there are bills to pay; He asks us to tithe because we need to be reminded that nothing we have belongs to us absolutely. So dependent are we on His grace, that without Him we would simply not exist. Giving ten percent of our goods in a thanksgiving sacrifice to God is a powerful way of living always in the humbling truth that we are creatures in need of redemption.
While tithing should be the norm for all followers of Christ, in the Catholic tradition Christians have never been asked to give the entire ten percent of their income directly to the Church. Rather, we are encouraged to give part of our tithe to the Church and the rest to other charities of our own choice. Our father in God, our Bishop Robert, asks us all to tithe in this way: 5% of our income to our parish; 1% directly to the diocese in the Bishop's Stewardship Appeal (BSA), and the remaining 4% to a worthy charity. Following this formula, any household can quickly determine the level of support which should be given to the Church.
Letter on Stewardship from Father Newman
I found this book while poking around online, which looks like it would be helpful if you're really ever interested in finding out how LDS patterns of giving compare to other churches:
Money Matters: Personal Giving in American Churches