Jesus went into the wilderness for 40 days to be tested. Rev Sally Hitchiner planned to put her spiritual armour on for four hours of desert-like silence with the leading atheist and evolutionary biologist, Professor Richard Dawkins.

She came away with her faith intact and a new concept for a television programme: "Richard Dawkins makes his confession."

Hitchiner, Anglican Chaplain and Interfaith Adviser at Brunel University and the founder of Diverse Church, a movement for young LGBT people, was, along with Dawkins, sitting for Sky Arts Portrait of the Year semi-final.

They had to spend two sessions of four hours each in each other's company, virtually motionless and allowed to do little more than engage in occasional small talk, as the semi-finalists competed for a place in this Friday's final.

After the two sittings, Dawkins said he felt he, Hitchiner and the artists had been on a marathon or a long-haul flight together. He was pleased with the portraits. "I find people often try to edit my eyebrows. I always resist these attempts."

Dawkins had been Christian as a child but on the programme he quoted St Paul to say he lost his faith as he grew up and "put away childish things". He clarified this to say he did not mean to imply that Ms Hitchiner's job was childish.

"I actually got on quite well with him," Hitchiner told Christian Today. She had been prepared for the encounter to be "particularly difficult", she said. "I went in there with my armour up." But it quickly became clear it she did not need to be on the defence.

"He said I reminded him of his daughter. "It was interesting, having to sit on the stage for hours with someone who has had strong arguments with a lot of Christian friends of mine, and to have to spend time with him without arguing. I found that we interacted like human beings. It was actually quite reassuring. I felt I saw the human side of Richard Dawkins, and a lot of religious people do not see that."

They could even become friends, she said. They are still in contact and have agreed possibly to meet for coffee in Oxford, where he lives and works. "It was a privilege to meet him. He was really interesting, fascinating. He told me lots of jokes."

They did discuss faith as the artists worked on their portraits. "He was very generous in a lot of the things he said. He still goes to things like carol services and finds the music very appealing. He also said there were things about the Anglican Church that he liked, or were the least bad option, which from him was a big compliment. He was trying to make an effort to get on and we did get on."

One reason they got on so well was because she was not setting out to prove him wrong, but just to sit amicably with him for the portraits. His public interactions with Christians are normally staged to be more confrontational. Because much of the sitting was done in silence, Ms Hitchiner had been planning to sit there and pray for his health and wealth.

But she forgot all about that when the time came, and instead made lists of birthday presents in her head.

She said she believed he might have become less tempestuous in his hostility to Christianity as he has aged, and now has a lot of positive things to say about it. The sittings gave her the idea for a television programme where she would interview Dawkins, with the title: "Richard Dawkins makes his confession." She said: "It would be TV gold, if someone was up for making it."