He admits that he is an agnostic who does not believe Adam and Eve were real, or that there is any proof the Virgin Mary gave birth to Jesus in a "gynaecological miracle".
From an ordained priest of 42 years who is now dean of the Holy Trinity Cathedral in Parnell and assistant bishop of Auckland, these are frank admissions.
He declared himself an agnostic in a column written for the Herald this week, saying the term could be used for someone who felt God's existence could not be scientifically proven one way or the other. "By that measure, I am an agnostic," he wrote.
The rebukes were swift: one letter-writer said his opinion piece was "frightening reading"; another warned "the Church must be careful lest it falls".
Bishop Randerson continued to describe himself as an agnostic in an interview with the Weekend Herald, saying he believed in God, but was more comfortable with God existing in forms such as "love" and "spirit" than as a supreme being.
He said he first believed in God as a supreme being but had changed his views over time.
He decided to speak openly of his agnosticism to rebut the "celestial teapot" thesis recently advanced by science writer and atheist Richard Dawkins: that belief in God is as silly as believing in a teapot.
Bishop Randerson said Dawkins had put up a "straw God" by attacking the traditional image of a supreme being and had been dishonest in failing to acknowledge that other views were widespread in Christianity.
The bishop added that Christians with traditional views - including strict Anglicans in his own congregation - could do just as much damage to the church as atheist attacks because they were "a real turn-off".
He knew his admission of agnosticism was "risky" and would upset some.
"For those who have grown up with a particular way, they will say that this is an abandonment of the faith. They will say: 'This is the way, we've always known this, you are saying something else, obviously we are right and you are wrong.'
"But I am also aware of those beyond the traditional believers who want to believe in God in categories that make sense to them."
Bishop Randerson said he was sensitive about how "agnostic" was defined and was uncomfortable with the Oxford Dictionary definition put to him by the Weekend Herald as a "person who believes that nothing is known or can be known of the existence or nature of God", which fits with common use of the word.
He preferred instead to focus on his doubts about God as a supreme being.
Such views are not new in the Anglican Church. In the 1960s, John A.T. Robinson, the bishop of Woolwich in England, wrote a book called Honest to God that challenged the ideas of "God up there" and "God out there". American John Spong, the retired bishop of the Episcopal Diocese of Newark, has called on Christians to rethink their views on God, Christ and the Bible.
In New Zealand, Lloyd Geering - a Presbyterian - has led the liberal charge. He was tried for heresy nearly 40 years ago after he admitted doubting the physical resurrection of Jesus.
Bishop Randerson could not name any other Anglican bishops who had gone as far as to publicly describe themselves as agnostic.
"But if you asked them, 'Do you believe in God as a scientifically provable entity?' the bulk of them would say probably say no," he said.
Bishop Randerson said he placed the resurrection in a different category from symbolic tales such as the virgin birth because the disciples had actually experienced it, even though it was hard to explain.
In his column Bishop Randerson also wrote that he felt "uncomfortable" leading prayers in public that had an exclusively Christian ending.
He said he was referring to gatherings where all faiths were present, such as Anzac Day, and the wording of the parliamentary prayer, which is under review. Prayers could have the same content without nailing it to one faith, so he had started leaving words "through Jesus Christ our Lord" off the end of prayers, saying "amen" instead.
"I would say to people who have difficulty with that to suppose the Anzac Day service was led entirely by Muslim clerics and every prayer had references to Muhammad and nothing else. They would say, 'Gosh, we're cut out of this."'
Why the bishop would marry a same-sex couple
Bishop Richard Randerson has criticised the Anglican Church's rejection of same-sex marriages, saying it "is not an expression of Christian love".
He said he would perform a civil union or same-sex marriage ceremony if it was permitted, but he did not think the church would change during his time.
During an interview with the Weekend Herald, Bishop Randerson cried as he spoke of the parents of gay and lesbian children who felt rejected by the church because of its stance and how they had thanked him for making them feel wanted through his opposition.
Bishop Randerson said he knew homosexuals in the church, including a close friend of 35 years, who had profound Christian conviction and "to say you've got it wrong, mate, I just couldn't do that".
He accepted it was not the church's view, but he believed the morality of a relationship was found by the love within it, not the gender of the people.
He believed the church would change its stance, but not for years.