A Baptist pastor says he stands by his email to a gay Christian author who he referred to as a "filthy child molesting fag".

"I pray that you will commit suicide," Pastor Logan Robertson of the Westcity Bible Baptist Church wrote in a response to an email from Jim Marjoram, who was promoting his book detailing his struggles as a gay Christian.

"We're not interested in your filthy lifestyle or book." Robertson said in an email now posted online.

"Romans 1 clearly says God has rejected homos and they are worthy of death. You cannot be saved...The bible says you are vile, strange (queer), reprobate, filth, sodmote, natural brute beasts, made to be taken and destroyed (2 Peter 2:12)."

Robertson then refused to speak to ONE news reporter, Matt McClean, who is gay, about the incident.

He allegedly told McClean that he would not give an interview to a "filthy faggot".

In a separate interview, however, he stood by his earlier claims. "I think every single one of them [gay people] should be put to death," Robertson said.

"Christians shouldn't be doing it. I'm not going to do it, it's the Government's job to be doing it."

His words have been condemned by the National Leader of Baptist Churches of New Zealand, Rev Craig Vernall.

Vernall confirmed that Westcity Bible Baptist Church is not a member of the union, and said he was "appalled" by Robertson's comments.

"It's unfathomable to be that any Christian would pray for someone to commit suicide," Vernall told GayNZ.com.

"We cannot and never would endorse his comments."

Robertson is described as having a "love for the lost" on his church's website, but Marjoram has said: "what you're preaching isn't love".

"And if you call yourself a Christian...Jesus wouldn't go anywhere near that," he added.