Gavin Ashenden, a former Anglican bishop who converted to the Catholic faith in 2019, said Philip "exemplified the kind of humility and self-giving that Christianity has at its heart."
"Baptized as a Greek Orthodox, he accepted the idiosyncrasies of Anglicanism for the woman he loved and at whose side he walked for eight decades," Ashenden said in a written tribute to the prince posted on his personal website.
"He exemplified patience, long-suffering, humility and kindness, when the cost of all of these virtues was demandingly high."
Ashenden, who is awaiting ordination as a Catholic priest, told Catholic News Service by Zoom April 11 from France that his father served beside Philip in the Royal Navy during World War II.
Philip was a 1st lieutenant aboard HMS Wallace and his father was a 2nd lieutenant, sharing the same bridge and wardrobe.
While serving as chaplain to the queen, Ashenden would sometimes speak of his father in conversations with the prince since he had grown up "hearing stories" about their service. His father once asked him to pass on a message to the prince.
"Philip was great," he said. "In his library the only thing he had more books on than theology was bird watching.
"The way he expressed his faith was essentially, I think, in trying to engage in diplomatic conversations between the major faiths."
"He didn't have much time for incompetence, so clergy who preached to the queen would always get a private message (from the prince) saying 'keep it short, they don't need to be converted by you,'" said Ashenden.
Ashenden served as chaplain to the queen from 2008-2017 but resigned from his post so he could publicly speak out against the reading of a chapter from the Quran at an interfaith service at St. Mary's Episcopal Cathedral, Glasgow, Scotland. The reading explicitly denied the divinity of Jesus.
Ashenden was received into the Catholic Church by Bishop Mark Davies of Shrewsbury two years after his wife, Helen, became a Catholic; he hopes to eventually serve as a priest of the diocese.
Philip, 99, died in Windsor Castle April 9, two months before he was due to celebrate his 100th birthday. He will be buried following a private funeral in Windsor April 17.