An Auckland Anglican church decided last night to take down its controversial Christmas billboard after an elderly woman slashed it with a knife - the third attack in two days.

St Matthew-in-the-City vicar Archdeacon Glynn Cardy said he was worried that people could be injured if there were any further attacks on the picture of Mary and Joseph in bed after sex.

The billboard went up on Thursday morning. It was covered in paint about six hours later and then went missing overnight. A replacement version was knifed yesterday evening.

Earlier, the parish defended the billboard, even though the Bishop of Auckland, John Paterson, had slammed it as "insensitive" and said he was disappointed at St Matthew's decision to continue with the display.

As the story spread around the world yesterday and church staff were interviewed on American TV stations, a defiant Archdeacon Cardy told the Herald: "I know what the bishop said. But at this stage we have no plans to take it down."

Archdeacon Cardy said the billboard was designed to let people outside the church realise that many Christians and church leaders did not believe in the literal virgin birth, and didn't believe that was the true meaning of Christmas.

"We're not out just to deliberately stir the pot. We're out to critique the idea of a male god impregnating Mary and the literalism of the virgin birth.

"The topic is ... something the church has talked about for centuries, but what is new is that we have the audacity to laugh at something quite so ridiculous as a male god sending sperm down to impregnate Mary."

Archdeacon Cardy said St Matthew's had continued to receive hundreds of emails and phone calls yesterday about the billboard.

Two-thirds had been supportive.

"Obviously we can't keep replacing it and there may come a time when we will have to take it down if the vandalism continues.

"But by then people would have known about it, laughed at it or even be offended by it and the billboard would have served its purpose."

Bishop Paterson said the billboard was insensitive and disrespectful.

"Discussion of theological perspectives is encouraged in a respectful way, but this approach is insensitive to communities across the Anglican Church as well as other denominations."

The bishop said there were a "multitude of issues" he would rather focus on this Christmas than the billboard.

"The season and story of Christmas is one that celebrates the life that is brought by Christ and that is the spirit of Christmas that I seek."