The Auckland Korean Churches Association has issued a public statement supporting Christian education in state schools.
In May, the Secular Education Network filed a case with the Human Rights Review Tribunal claiming that preferential treatment of Christianity in schools was prohibited under the Bill of Rights.
Association spokesman Andrew Moon said members had been "shocked" by recent developments, and the statement was issued "on behalf of 10,000 Korean Christians" here.
It said Christian teachings in school have had positive effects on many Kiwis, regardless of whether they were Christians or not.
"Throwing away Christianity...under the pretence of respecting other religions does not mean merely excluding Christian religion, but throwing away the traditions and values of Christianity," the statement said.
It argued that the religious education classes were not a method of indoctrination, but rather a means of support for moral education.
Moon said the statement in Korean has been circulated in member churches and published in local Korean media.
The association plans to release an English version this week, opposing the views of the network.
The association represents most Korean protestant churches here, including the Korean Methodist Church, Korean Presbyterian Church and the Korea Assemblies of God in New Zealand.
"Korean Christians feel very strongly about this issue because many chose to move here because it's a country built on Christian values," Moon said.
"Many are hopeful that our next generation will be able to continue to learn Bible values at school."
Businessman Young Min Choi, 50, said one of the main reasons he migrated with his family to New Zealand in 2009 was because of its values.
"One of the main reasons was because we liked what New Zealanders value the most; a family oriented culture, welfare and honesty," Choi said.
"I think these values were fundamentally built upon Christian teachings."
Esther Kim, 37, who moved to New Zealand in 1995, said her children, 5 and 7, enjoy Bible lessons at school.
"They say it's fun and are absolutely enjoying it," Kim said.
"The classes are helpful to my children ethically and also emotionally."
Secular Education Network spokesman David Hines, a retired journalist and lay preacher, said he was "surprised" by the association's claim that many Korean Christians had chosen to live here because "New Zealand was built on Christian values".
"We are not trying to shut out teaching about Christianity, but we insist this teaching must include non-Christian religions and non-religious beliefs such as a atheism and humanism," Hines said.
"We want the law tightened to ensure that these lessons are taught in a neutral way, so that children from all these backgrounds will feel at home, and not treated as second-class because they are not Christians."
The network is seeking rulings from the Human Rights Commission if the Education Act, by allowing religious favouritism in state schools, was in breach of the Bill of Rights.
For his case, Hines had gathered 26 witnesses including parents who said their children were mistreated.
"We have received $37,000 donations towards our legal costs, and it comes from diverse people, including people from different religions and no religions," he said.
The number affiliated with Christianity in New Zealand has declined since the 1990s.
In the 2013 census, just under half of the population were Christians, while 42 per cent stated they had no religion.