BOSTON - Who would have believed that Christmas would provide a "teaching moment" for sex ed?

The folks at the Rapides Station Community Ministries of Louisiana bubbled with pride as they reported, indeed bragged, that "December was an excellent month" for abstinence class.

"We were able to focus on the virgin birth," they wrote, "and make it apparent that God desires sexual purity as a way of life."

June, however, is probably not such an excellent month.

The other day, the American Civil Liberties Union took Louisiana to court, claiming that the state was using public money to teach Christianity. Sex ed, they said, was really religious ed.

This court appearance also provided another "teaching moment": on constitutional law. The Louisiana providers didn't tiptoe across the line separating church and state. They ignored it.

Public funds went to one group that took field trips to abortion clinics for prayer vigils. Federal and state dollars paid for a "Passion 4 Purity" program that taught abstinence through "scriptural concepts."

The state even funded the arts: a roving troop of "Just Say Whoa" players who told students that sex outside of marriage is "offensive to God."

Ah yes, your tax dollars at work.

In the courtroom, Dan Richey, the state program's administrator and former news director of a fire-and-brimstone radio station, admitted rather cavalierly that some programs may have promoted religion: "Those things will happen." He promised tighter controls in the future.

The ACLU has nevertheless asked the court for more accountability. They want to ensure that public dollars aren't translated into religious messages and/or handed out to contractors from religious institutions.

Whichever way the court eventually rules, the Louisiana case couldn't come at a better time. After all, the Bayou State has been teaching the gospel of sex education with money allocated under the 1996 welfare reform bill.

Now the Senate is about to take up a new welfare reform proposal - already passed by the House - that would up the ante. It would distribute $50 million a year to abstinence-until-marriage programs across the country.

Indeed, if the Bush administration gets its way, there will be $135 million in three different federal pots dedicated to a sex-ed curriculum that fits on the T-shirt worn by a star pupil in Louisiana: "Abstinent I will stay until my wedding day."

Now let it be said that most parents, in or out of Louisiana, favor abstinence ... at least for their children.

American parents also have a realistic two-pronged approach to protecting children, especially teen-agers. Today, 70 percent of 18-year-olds have had sexual intercourse. It's not a surprise that 82 percent of parents want sex ed to cover contraception as well as abstinence.

The problem with the abstinence-only classes isn't just that the groups receiving the dollars read like a who's who of the religious right. It's that programs preaching - excuse me, teaching - this are spreading fear, misinformation and disinformation.

Under federal guidelines, this money can go only to a program that has "as its exclusive purpose teaching the social, psychological and health gains to be realized by abstaining from sexual activity."

The money is to teach, specifically, "that abstinence from sexual activity is the only certain way to avoid out-of-wedlock pregnancy, sexually transmitted disease and other associated health problems."

And for extra measure, "that sexual activity outside the context of marriage is likely to have harmful psychological and physical side effects."

They can't talk about contraceptives, except to emphasize the failure rates. Call it the bad news gospel.

"This is a classic example of ideology trumping public health," says James Wagoner of Advocates for Youth.

It isn't just inaccurate education. It's ineffective. There is no proof that the half-billion dollars already spent in abstinence-only lessons delays intercourse or prevents pregnancy.

Is it any wonder that the abstinence-only supporters in Congress have fought amendments that would require the lessons to be medically accurate? I guess we're supposed to take the value of abstinence-only education on, um, faith.

Faith-based politics? Faith-based sex education? Welcome to the United States of Louisiana.

Ellen Goodman is a columnist for The Boston Globe. Her column appears Mondays and Thursdays in The Sun. She can be reached via e-mail at ellengoodman@globe.com.