Tithing – of all the churchy words, it has to be the churchiest, don't you think? Aunt Edna, tea-cakes, and tithing. It's a slippery little word: it has always sounded to me like the sound snakes would make, if they spoke with ts instead of ss. Actually, if you did not know what tithe meant, you might think it was something criminals did. Tithe may be the only word in the English lexicon that sounds both ecclesiastic and criminal.

I came to tithing somewhat unwillingly. As a new Christian, and a grad student living on a whopping $8,000 a year, I balked when a priest challenged me to give away $800 of that $8,000. Like the newlywed who insists on keeping separate checking accounts, I was happy for Jesus to have my heart, but I wasn't crazy about sharing my money with him. This priest, though, was insistent. He promised me that if I would commit to tithing for one year, before the year was up, I would love giving away money. The Life cereal approach to charitable giving: try it, you'll like it. Remarkably, he was right—I found that I actually enjoyed writing that $67 check every month. Giving away money took me out of my grumbling resentment about being too broke to afford food more pricey than the proverbial Ramen. When I wrote those checks, I stopped being a poor grad student and became, briefly, a benefactor.

If there's a psychological benefit to tithing, there are also spiritual and social benefits. It is charitable giving that makes organizations like churches possible. That is, one reason tithing is important is that it helps pay your pastor's salary, helps keep the lights and heat on in your church. And it is tithing, more than any other spiritual discipline, that has fostered in me some sense of gratitude and reliance on God – giving away a chunk of money helps us remember that it's not our money to begin with.

As we near the middle of April, it's worth considering an additional benefit of tithing: the tax benefit.

Exactly how does that tax benefit work? Charitable giving reduces the amount of taxable income you have – so the more money you have, and the higher tax bracket you're in, the more you benefit from giving money away. Remember, you can also claim charitable deductions for gifts other than cold, hard cash. For example, if you drive across the state to build a Habitat for Humanity house, you can deduct $0.14 per mile, though you can't claim a deduction for your time. (Some churches hold that people ought to give 10% of their income to the church, specifically, and other charitable support should be above and beyond that sum – the federal government, of course, doesn’t make such distinctions, and rewards your giving money to any sort of charitable organization, be it a church or synagogue, a university, hospice, or the Sierra Club.)

Caveat lector: do check with a certified accountant before claiming your charitable deductions. Those detail-minded CPAs have all the exemptions, qualifiers, asterisks, and loopholes at their fingertips. Exceptions notwithstanding, charitable giving can add up to significant savings on your taxes.

Is there dissonance between the spiritual discipline of giving money away and the material benefit of getting a tax break by doing so? Perhaps – though, even with the tax break, you will always end up with less money than if you hadn't donated anything to charity. And, as Bill Sheppard, an accountant in Americus , Georgia , told me, "If you're tithing just to receive the tax benefit, you've probably missed the point."

If the current tax bracket system means Americans don't all benefit equally from giving away money, the truth is that we also don't give equally. A 1998 article by sociologists Mark D. Regnerus, Christian Smith, and David Sikkink found that religious people tend to give more money to charitable organizations that support the poor than non-religious folks, and theologically conservative Protestants give more to relief charities than Catholics and liberal Protestants. When this finding was first published, the pundits were puzzled: religious conservatives don't tend to support poor-friendly policies like welfare entitlements, so why do they give more money to the poor?

Yet, upon reflection, the finding makes a great deal of sense. For starters, theologically conservative people are not, as Jim Wallis endlessly reminds us, always politically conservative. And even an evangelical Republican forking out money for poverty relief should be no surprise -- giving money helps individual poor people without contributing to the social programs that political conservatives disapprove of. Political conservatives committed to "small government," might give more to help poor people because they believe that people, not the government, should oversee relief.

More recent data on American giving comes from a December 2005 Gallup poll, which showed that age, church affiliation, and income level all have an impact on willingness to give. The more money you earn, the more likely you are to give money away – 74% of households earning $30,000 or less gave away money in 2005, 90% of households earning between $30,000 and $74,999 gave money, and 96% of Americans living in households earning $75,000 or more gave away money. Unsurprisingly, middle-aged Americans are more likely than 20-somethings or senior citizens to give away money. Finally, while people who go to church regularly are much more likely than non-churchgoers to give money to religious organizations, they are only slightly more likely to give money to non-religious charitable organizations.

The devil can quote statistics, of course, and other studies, such as a 2003 article by Wharton School scholars Edward Buckley and Rachel Croson, show that poor people are likely to give a higher percentage of their income than rich people: think of this as the syndrome of the widow's mite, the poor woman in the gospel of Mark who gave her entire savings, two coins, to the Temple (and whose small contribution Jesus deems worth more than the huge contributions rich people gave, because the rich "gave out of their wealth; but she, out of her poverty, put in everything.")

But most of the studies agree that, on the whole, Americans don't give a very high percentage of their income away: A 2005 Barna study suggested that "the typical individual gave away about 3% of their income." That figure is significantly less than the biblical standard of 10%.

Why do Americans only give away 3% of our income? Because, though 3% might pinch, it doesn't pinch very much. 10% is harder. A commitment to give away 10% of your hard-earned salary requires serious self-sacrifice – it might require buying a smaller home, with a smaller mortgage payment. It might require scaling back vacation plans, passing on that trip to Europe and renting a modest house at the beach instead. It might require telling your kids "no" more often. It might require a family of two kids and two adults to own only one car, and that car might not be a shiny, new SUV.

The discipline of giving away money may be a place where our seemingly private spiritual lives meet the world's very public needs.

Those lessons, those benefits of giving, are far more valuable than the tax break.