A choir member at Crossroads Christian Church in Corona, Calif., stole more than $50 million from church clients through a fraudulent investment firm he named JTL or Just the Lord.

Although the staff knew nothing about it, a member of Rick Warren’s Saddleback Church also bilked investors out of $50 million by presenting his company as a group of faithful Christians and distributing copies of "The Purpose-Driven Life."

At a church near St. Louis, a man used his church connections to persuade members to sink several million dollars into a real estate investment plan—none of which was ever invested.

Securities regulators say investment scams represent a $40 billion a year industry in America—and many of the victims are church members. In some cases, the entire congregation gets taken for a ride.

The most recent survey by the North American Securities Administrators Association (NASAA) found that over a four-year period more than 80,000 people nationwide had lost nearly $2 billion to religious-based investment scams.

"We have every reason to believe that con artists are preying on the faithful like never before," says Bob Webster, NASAA’s director of communications. "We call it ‘affinity fraud,’ where they victimize people in a certain group, whether it’s a church, ethnic group or a profession."

Barry Minkow is an expert on fraud. He served more than seven years in prison after boosting the ZZZZ Best Co. to a $300 million stock evaluation by overstating revenues and hiding losses. The company never turned a profit.

Since becoming a born again Christian and the pastor of a Bible church in San Diego, Minkow has established the Fraud Discovery Institute. Working undercover with legal authorities, over the past three years the institute has shut down 16 fraudulent schemes, with two more cases pending.

Minkow thinks teaching on stewardship has focused too much on getting out of debt and not enough on gratitude and practical steps for people to avoid becoming victims of fraudulent operators.

"I don’t think we do a very good job of teaching people what not to invest in," Minkow says. "As leaders, we have two roles. One is to increase stewardship to mean not only (avoiding) debt, but not falling into greed."

While saying victims shouldn’t be blamed for a swindler’s fraud, Minkow says Christians fall into traps when they unrealistically look for guaranteed returns of 20 to 40 percent.

Minkow asks: If the best legendary investor Warren Buffett ever did was 24 percent a year, why would anyone believe a con artist promising higher returns?

What’s even worse than investors falling for obvious con games is the impact; lately he says swindlers have made retirement funds their favorite target.

Minkow says there are basic steps anyone can take to prevent themselves from being victimized, such as using an Internet search engine to check on the person making the offer.

He says reputable businesses usually leave a trail of links to press releases, newspaper articles and other material.

In addition, Minkow says pastors should be suspicious of obvious signs of a conflict of interest. For example, a newcomer peddling investments and promising his only interest is raising money to help the church’s building fund or other altruistic-sounding motives.

Prospective investors should also be wary of any business model that doesn’t have a realistic basis. Among the stories con artists like to use are they can pay big returns because they finance loans for businesses that normally can’t get them or they loan money to banks, Minkow says.

In short, question anything that sounds too good to be true.

"That’s what people in churches don’t ask, the obvious," Minkow says. "If somebody could make 30 to 40 percent a year, they could double their money every two and a half years. What do they need your money for?"

Ken Behr, president of the Evangelical Council for Financial Accountability (ECFA) in Winchester, Va., says get-rich-quick schemes don’t have to be lucrative investment frauds.

One con he says often victimizes churches is a multi-level marketing deal that essentially is a pyramid scheme. Another is the theft of donations by a treasurer, secretary or other person in a position of trust.

"Be careful of people using Christian terms (to sell something)," Behr says. "Christians tend to be more trusting of other Christians and as a result they let their guard down and become easy prey."

The chief operating officer of a large church in Pittsburgh before coming to ECFA last March, Behr says when he taught stewardship he stressed that giving needed to be sacrificial, ongoing and proportional to one’s resources.

Instead of looking to Scriptures that promise blessings—which often get translated as money or material goods—Behr believes in embracing generosity and focusing more on what you can give than what you can get.

"I think that’s the best way to minimize fraud," Behr says. "If we have a spirit of contentment along with gratitude, we don’t look for ways to get more."

Click here for Part 1: Stewardship: Why pastors should teach more broadly about giving.