For some, a Senate committee's investigation into six well-known evangelical ministries is long overdue, a needed check on preachers living lavish lifestyles built with their donors' generosity.

But even among those who welcome the scrutiny, there was concern Wednesday over government intrusion into religion, more red tape in the name of transparency and undue burdens on preachers and churches who play strictly by the rules.

The top Republican on the Senate Finance Committee, Chuck Grassley of Iowa, faxed letters Monday to a half-dozen evangelical mega-ministries requesting information about compensation, board oversight and perks — from luxury oceanside homes to flights on private jets to opulent spending on office furniture.

The organizations are not legally required to respond. Some have released statements pledging to cooperate, others have hedged and all have emphasized their commitment to following applicable tax laws.

The IRS requires that pastors' compensation be "reasonable," a figure set by collecting comparable salaries and weighing factors such as church size and a pastor's value to the congregation. IRS rules prevent pastors and other insiders from excessive personal gain through their tax-exempt work.

Marvin Olasky, editor of World, an influential conservative Christian magazine, credited Grassley for racheting up the pressure on ministries he believes are far too secretive about how donations are spent.

"These organizations should be pressured to disclose information," Olasky said. "If glasnost worked in the Soviet Union, it can work in relation to these ministries."

Olasky, however, cautioned that "hard cases make bad law." Echoing others, Olasky said governmental action should be a last resort and that the Christian community and media needs to press organizations to be more open.

The six ministries in the inquiry share Pentecostal theology, a strong television presence and a "prosperity gospel" message emphasizing material rewards for the faithful. They are:

_ Randy and Paula White of Without Walls International Church and Paula White Ministries of Tampa, Fla.

_ Benny Hinn of World Healing Center Church Inc. and Benny Hinn Ministries of Grapevine, Texas;

_ David and Joyce Meyer of Joyce Meyer Ministries of Fenton, Mo.;

_ Kenneth and Gloria Copeland of Kenneth Copeland Ministries of Newark, Texas;

_ Bishop Eddie Long of New Birth Missionary Baptist Church and Bishop Eddie Long Ministries of Lithonia, Ga.;

_ Creflo and Taffi Dollar of World Changers Church International and Creflo Dollar Ministries of College Park, Ga.

These kinds of huge, non-denominational operations are like smaller churches in that they aren't required to publicly disclose their finances.

Scott Thumma, a megachurch expert at the Hartford Institute for Religion Research, said they require even greater scrutiny because they lack denominational oversight and have a penchant for unchecked lavish spending.

"If this attention makes these ministries more accountable to donors, it's probably a positive step forward," Thumma said. "At the same time, it does pose challenges about what is the role of government in how a church spends its money and who is accountable. These are probably legitimate concerns by those pastors watching from outside."

Some pastors, Thumma said, might be hesitant to speak out because "they are looking at that slippery slope and don't want to be seen as advocating for the government getting involved in the roles of church."

Dollar released a statement saying questions raised by Grassley's inquiry "could affect the privacy of every community church in America."

Others question whether the halls of Congress are the appropriate setting for the debate.

"I do wonder why a Senate committee would be doing this when the IRS is perfectly capable of enforcing its own rules — and does so frequently," said James Bopp, a nonprofit and tax lawyer who represents several large evangelical organizations but none of those under investigation.

Tom Minnery, a senior vice president at the evangelical media ministry Focus on the Family, said he was disappointed that Grassley thinks an investigation is necessary. Minnery called existing tax rules "vigorous."

In an interview Wednesday, Grassley said his committee has jurisdiction over nonprofits and oversight over the IRS. He said it's unclear whether the IRS is doing enough to police Christian nonprofits or whether existing guidelines go far enough — questions that are part of the inquiry.

"We're going to let these ministries speak for themselves," he said. "Hopefully, it comes back everything's OK, but the allegations we've heard about raise questions."

Grassley also said the inquiry will not delve into doctrinal issues, and that he understands church-state separation concerns. At the same time, he said religious nonprofit groups should be expected to follow rules governing nonprofits just as secular groups are.

"I'm hoping these organizations clean up their own act if there's something wrong," Grassley said.

An IRS spokeswoman declined comment on the Grassley investigation, which could lead in several directions: public hearings, more ministries being drawn in, and potential penalties ranging from back taxes to loss of tax-exempt status.

The evangelical nonprofit world already polices itself through the Evangelical Council for Financial Accountability, which requires members to annually submit audited financial statements and answer other transparency questions. But membership is voluntary, and none of the groups under investigation belong.

IRS audits and inquiries into nonprofits, meanwhile, are confidential. Even if a Christian ministry is punished, donors don't learn about it unless the organization under scrutiny makes it public.

"I see this as a kind of a tug of war of interests," said Rodney Pitzer, managing director of research with MinistryWatch.org, which grades Christian groups on financial accountability.

"On one side you have a ton of good ministries out there who want to be unshackled from red tape and government bureaucracy. In that midst unfortunately are wolves in sheeps' clothing."