I'm curious on how you view tithing in the context of taxation.
Governments have taken upon themselves to help those in need, and taken from the population to do so. Could one not argue that a certain proportion of your income has already gone to charity? (presuming you're paying income taxes)
Part of giving to charity in addition to taxes is that I don't think the government (USA) is really handling my money properly when it comes to social programs. Private giving in the USA allows us to choose how our money is spent more specifically and usually lets you make a bigger impact in an area you care about. You should look up private giving in the USA, it's an astounding figure that is given every year voluntarily, there are tax deductions if you itemize, but at the end of the day I would save more money taking the standard deduction and not giving, so it's still a sacrifice monetarily for a lot of people here.
Governments have taken upon themselves to help those in need, and taken from the population to do so. Could one not argue that a certain proportion of your income has already gone to charity? (presuming you're paying income taxes)