Since 1982, the tithe has been the minimum standard of giving in the Episcopal Church. We are not alone in that teaching. Americans donate $295 billion a year to charity, with just under a third of it - $97 billion - to religious organizations. But the typical American Christian gives about 2.5% of their income to church.
Now some Christians are beginning to question the centrality of the tithe. In an era when contributions to religious groups are growing more slowly than other charitable giving, and as Congress takes a closer look at the finances of some televangelists, CBS Eye on Religion Reporter Martha Teichner examines the controversy over tithing, and meets some inspiring people who strongly believe in the power of generosity.
From his home near Marietta, Georgia, Russell Kelly wages war against preachers who use the Bible to justify tithing. His Web site, shouldthechurchteachtithing, argues against the supporters of tithing.
"We believe if you look at those texts they quote," he says, "they are out of context."
But that's not his only objection.
"Almost every person I contact on the Internet, they tell me the same story, where they go to their pastor - no matter what kind of church it is, Baptist, Charismatic, Methodist, you name it - and start asking questions about tithing, they are told to shut up, to be quiet, to leave the church."
It happened to his own wife, when her first husband was dying.
"I had a $5 an hour job, a small child to raise, and my husband kept getting, sicker and sicker," Janice Kelly told Teichner. "It came to the point whether I buy insulin for him or whether I pay my tithes, so I went to the preacher."
Janice Kelly didn't expect his response.
"He just ... told me I would be cursed."
Americans have been trying to figure out how to support their churches ever since they severed themselves from the taxing power of the state and stopped charing pew rents and other forms of membership dues.
"Protestants, both mainline and evangelical, have since the 1870s, fixed upon the tithe and on this Malachi passage as a kind of law that has never been repealed," explains James Hudnut-Beumler, dean of the divinity school at Vanderbilt University.
Yes, only since the 1870s, as a way of making up lost revenue. The First Amendment in effect privatized religion in the United States, cutting off the tax money that once supported it in colonial America. The weekly collection didn't even exist until the middle of the 19th century, when churches gave up selling or renting pews.
"I'm somewhat suspicious of people who want to turn giving ten percent into virtually the only law that applies to people who are under a covenant of grace," says Hudnut-Beumler, "where God saves freely, not for ten percent down."
He says he's reminded of Martin Luther, father of the Protestant movement, who broke away from the Catholic church because it was selling indulgences: Promises of a quicker road to heaven in exchange for cash.
"Stripped down to its basics," he says, "I don't think it's different than indulgences. What we see today, though, is a return to 'this-for-that religion,' give God this and God will give you that."
Of course, the lavish lifestyles of some televangelists and other religious leaders has given the tithe a "black eye" according to some Christian financial planners, and has caused some to ask if donors are being exploited.
Iowa Senator Charles Grassley wants to know how God happened to give the trappings of a billionaire lifestyle to certain televangelists and whether donors, many of them tithers, are being exploited.
Grassley, a ranking member of the Senate Finance Committee, has requested financial records from six highflying ministers' accounts of their spending on everything from houses to jets.
One evangelical Christian who works as financial planner says he advises his high-income clients to start with 10% as the minimum level of giving.
"Tithing is a matter of obedience," says financial planner Bruce Williams. "To start with, it is commanded by the Bible."
Williams counsels his clients to start at ten percent.
"I would say 75 percent of the people I work with are already tithing or well beyond that. They are a generous lot."
Williams manages the Nashville office of Ronald Blue & Co., a kind of faith-based Merrill Lynch, with fifteen offices around the U.S., that urges high net-worth believers to build giving into their financial planning, but with this caveat:
"Any giving should be done cheerfully and not under compulsion," says Williams. "It's a matter of the heart."
Read: CBS Sunday Morning: To tithe or not to tithe
See what the Episcopal Church has had to say about the tithe. Here is a list of General Convention actions since 1982 concerning stewardship and, specifically, the tithe.