If you visit Ireland after October, you'd better watch what you say about God.

A blasphemous slip of the tongue could cost you 25,000 euros under revamped legislation that will soon be signed into law.

Blasphemy is an act of challenging or offending a religious belief.

In recent years, western countries such as England have been taking blasphemy laws off the books, or changing their focus so that they cover hate-related crimes in general. Ireland has taken a different approach, updating its legislation but maintaining a focus on religion.

In Ireland, it has been a crime to publish blasphemous material since 1961, although nobody has ever been convicted. The Seanad, the Irish senate and upper level of parliament, passed the Defamation Bill in July that makes uttering blasphemy a crime as well.

The bill was originally proposed in 2006. It worked its way through parliament and received final approval on July 10 this year, when it passed by a slim margin of 23-22.

Lorraine Weinrib, a law professor at the University of Toronto, says the bill is a modern update of blasphemy laws.

"I don't see this as a new thing as much as an old thing that hasn't quite disappeared in Ireland," she says.

"Unlike the old blasphemy laws which only protected the dominant religion [Roman Catholicism] … this one seems to protect all religions, so it kind of has a modern equality bent to it," Weinrib adds.

But blasphemy laws can have an impact on freedom of expression, Weinrib says.

"They create a crime where one of the basic elements of the crime is subjective outrage of particular people. So there's really no objective measure, and this can cause a disruption in the modern understanding of the relationship between religion and the public space of a liberal democracy."

Even so, Weinrib points out that under Ireland's new legislation, in order to be found guilty, there has to be proof that the offender intended to cause outrage with a statement that is abusive or insulting. The statement also has to produce a violent reaction.

The bill states that a person publishes or utters blasphemous matter if:

He or she publishes or utters matter that is grossly abusive or insulting in relation to matters held sacred by any religion, thereby causing outrage among a substantial number of the adherents of that religion.

He or she intends, by the publication or utterance of the matter concerned, to cause such outrage.

The bill puts the onus on a defendant to prove that a reasonable person would find genuine literary, artistic, political, scientific, or academic value in the matter to which the offence relates.

"I think we're talking about central issues — for example, a depiction of Christ as a homosexual … many religious people find this outrageous and their reaction is intense," says Weinrib. "The intent of the outrage still needs to be proven in this case."

Ireland is not alone in having laws that take aim at blasphemy.

Canada lists blasphemous libel as a crime under the Criminal Code, which carries a penalty of up to two years in jail. But the Canadian Charter of Rights and Freedoms guarantees free speech rights that supersede the blasphemy law.

The Canadian code says, "No person shall be convicted of an offence under this section for expressing in good faith and in decent language, or attempting to establish by argument used in good faith and conveyed in decent language, an opinion on a religious subject."

Many countries have abolished their blasphemy laws in recent years. In Britain, the Church of England (and by default, Christianity) was protected from blasphemy up until last year when the government reviewed the law. The U.K. voted to abolish blasphemy laws on Jan. 10, 2008.

In the United States, blasphemy has never been considered a crime.

In countries where Islam is the state religion, blasphemy is still considered a serious offence. In countries like Pakistan and Afghanistan, the penalty for blasphemous crimes can be execution.

A number of Islamic countries have been pursuing an international anti-blasphemy resolution at the United Nations that would restrict any speech that is offensive to any religion. But that approach assumes everyone is religious, Weinrib says, and issues can crop up when two religious groups have contradictory points of view.

Here are some significant historical events involving blasphemy: