For generations of pupils at Midhirst's closeknit primary school, the weekly routine included half an hour of religious instruction.

"No-one ever opted out and the children loved it," principal Stuart Beissel says.

"Things have changed over the years. We don't have all the people going to church any more, but I think people still hold the basic values of the Bible."

But after decades without interruption, religious instruction has ended at Midhirst.

"All the great people that took religious instruction moved out of the district or retired," Mr Beissel says.

It's a trend being seen across the country. A survey of 1800 primary and intermediate schools carried out by rationalist David Hines showed 62 state schools had dropped religious instruction since 2011, mainly because of a lack of volunteers able to teach it.

More alarming to many was that while classroom religious instruction is decreasing, one third of state schools surveyed still allow it, despite the country's legal commitment to a secular education system.

In Taranaki, religious instruction is still on offer in at least 16 state schools; 11 of the 69 in the province did not respond to the survey.

Stratford School principal David Cripps sees the appropriateness of facilitating a Christian or religious influence in a secular state school as an issue cloaked in complexity. And, although a lack of volunteers means his school no longer has to grapple with the issue, he believes knee-jerk reactions for or against offer woefully inadequate answers.

"The amount of people involved in religion throughout the world is obviously very large, so by not addressing that, are we doing our children a disservice in some form? It's a big issue. It's a tricky one. It's not easy," he says.

"I just think it's really important that we remember, in terms of education, we give the children the best possible opportunities when talking about religious instructions, or hauora or spirituality. I think we need to be open to explore and find out what that looks like in a government-run school."

At Oakura's decile-10 primary school, the "look" of religious instruction has changed over the years. From a half-hour lesson each week with volunteers teaching unsupervised in classrooms, it has evolved into two or three assembly-style lessons a term.

Parents were recently asked if they wanted it to continue and the majority did, principal Lynne Hepworth says. They see it as an opportunity for their child to be informed about Christianity, she believes.

"Parents are welcome to come along and the group nature of the lessons mean there is no opportunity for a teacher to go off on a tangent."

The tangent opponents fear is when instruction veers off into evangelism - the preaching of a set of religious beliefs with the goal of conversion.

The Churches Education Commission is used to dealing with accusations of evangelism. Last year, it came under fire for a pamphlet it sent to members in which its director, David Mulholland, wrote that schools were an "underutilised mission field".

The commission supplies a religious instruction syllabus for more than 100 schools across the country, 12 of those in Taranaki.

Mr Hines has no problem with the values included in the commission's Christian Religious Education curriculum, but criticises the presentation of them as "things one must do to please God".

On the other hand, the commission's "code of expectations" for its volunteers states they are there to "provide basic information to enable the students to make informed choices without any pressure for commitment".

"It's all about the language we use in the classroom to make sure teachers don't overstep their boundaries," commission chief executive Simon Greening says.

"The code says no evangelism and we make sure that doesn't happen. Yes, we will talk about gospel stories of Jesus healing someone, but the focus would not be on the healing, but compassion as a value."

The lessons are so tightly structured and so benign, Mr Greening says friends of his who do not go to church are totally open to their children having a half hour of religious instruction each week.

"It's the ‘what's the harm' theory," he says.

The campaign against such instruction is not coming from parents, he says, but from a group committed to the view that religion is "not a good thing".

"We are not talking about a band of angry parents. I think that's important. These people are committed to an atheistic world view because they are anti-Christianity or anti-religion.

"I think that sometimes doesn't come through in the media. It sounds like these are just good old-fashioned Kiwi parents. Context is everything," Mr Greening says.

And so does Mr Hines, who sees greater danger in what the religious lessons omit than in what they include.

"Even the more moderate ones are doing harm, because they are creating an impression that Christians are the only people who have got any moral values.

"I asked a principal who just cancelled Bible In Schools - I said ‘would you say it's biased?' - he said it was biased by omission. They mention there are good Christians around. They don't mention there are good Muslims and Hindus around, so they create a bias by just what they don't say."

The bias is not just against other religions but against those without religion - a group to which 36 per cent of the population claimed to belong in the 2006 census. Should trends continue, the 2013 census is likely to show this group has grown to 40 per cent.

This is a stunning turnaround from 1956, when just 0.5 per cent of New Zealanders indicated they had no religion. But it was in that religion-soaked climate that the Education Act 1964 was passed and it is this act that allows religious instruction in otherwise secular state schools.

"Religion is part of a bigger picture of philosophies of life and a lot of those philosophies are of no religion at all," Mr Hines says.

To the Dean of Taranaki Cathedral Church of St Mary, Jamie Allen, the appropriateness of religious instruction in state schools depends on both content and intent. The purpose of teaching must include understanding, valuing and appreciating story, identity and spirituality but "never indoctrination".

"The Christian faith is deeply woven into so much of our cultural tapestry, and the opportunity to learn the reasons for, for example, the key festivals which so many of us celebrate makes sense," he says.

"Why do we give presents on December 25th? There is obvious benefit in knowing the answer to that question.

"Education is nothing to be afraid of and yet there seems to be such a reaction akin to fear to this particular subject."

Having religious instruction on offer is better than not having it on offer, he believes, as it allows parents to choose what their children are exposed to and to opt out if they do not wish to engage.

WHAT IS A SECULAR STATE?

A secular state or country is officially neutral in matters of religion, supporting neither religion nor irreligion. It treats all citizens equally, regardless of religion or non-religion, and does not have a state religion. New Zealand has never had an official religion, and the church and state have always been separate.

A SECULAR EDUCATION

The Education Act 1964 requires that all teaching in primary schools must be secular. A secular education should not favour any particular religious beliefs.

The act enables primary schools to provide religious instruction and religious observance, but only in a way that does not discriminate against anyone who doesn't share that belief. Students must also be able to opt out freely.

An example of religious observance is prayers said in a school assembly. Religious instruction means teaching aspects of a faith in its own right. It carries an implicit or explicit endorsement of a particular faith.

Schools are officially "closed" when religious instruction takes place. This is considered to be consistent with the requirement that state primary schools be secular.

The overwhelming majority of religious instruction in New Zealand is on the Christian faith.

Schools can provide religious education without restriction. Religious education, also commonly called religious studies, refers to teaching about religion(s) as part of a broader context. It does not require students to engage with the religions being studied.

Private and integrated primary schools, such as New Plymouth's St Joseph's Primary School and St John Bosco School, are not obliged to provide a wholly secular education. If they have a special character provision that is religious in nature, the school can offer religious instruction without closing.

Kura Kaupapa Maori are primary schools that follow Te Aho Matua (a holistic approach to children's development based on Maori cultural and spiritual values and beliefs) and teach in Te Reo Maori. Although they have a "special character" they must be secular when the school is open.

Source: Religion in New Zealand Schools, Questions and Concerns 2009 - Human Rights Commission.

THE SURVEY

Rationalist David Hines describes himself as a Christian atheist and liberal Methodist minister. He is against religious instruction in schools. Over the last 10 months he wrote to 1800 state primary schools in New Zealand with official information requests about Bibles in School programmes. He released his findings last Saturday.

578 schools have religious instruction classes.

62 schools have dropped religious instruction in the past two years mainly because of a decreasing supply of religious instruction teachers and a need for more time for other education.

1000 schools received letters from Ombudsman's office to encourage them to take part in the survey. Under the Official Information Act 1982 state schools are obliged to provide information upon request.

260 schools are yet to respond to the survey.