Canon AM Allchin: Theologian who fostered unity between Christianity’s major strands

The Anglican theologian AM Allchin wrote prolifically on Christian spirituality and, in particular, the relationship between Eastern Orthodoxy and the Christianity of the West. During a distinguished life as priest and academic, he strove to foster an awareness of the underlying unity between the major strands of Christianity, throwing new light on our understanding of diverse traditions and belief systems. He travelled widely, making available what he had experienced in places like Mount Athos and Romania in lectures, conferences, pamphlets and a score of books that are among the most readable, and stimulating, studies in their fields.

Arthur Macdonald Allchin, known as Donald, was born in London in 1930. During the Second World War Westminster School was evacuated to Malvern where he sang choral works in Worcester cathedral. From there he went up to Christ Church, Oxford, before studying for the priesthood at Cuddesdon College. His MA thesis was later the basis for his book The Silent Rebellion (1958), which became the definitive account of the 19th-century revival of the religious life in the Anglican church.

From 1956 to 1960 he was curate of St Mary Abbots in Kensington and librarian at Pusey House in Oxford from 1960 to 1969. His time at Canterbury, from 1973 to 1987, was particularly fruitful in the contacts he made with Roman Catholic communities in Europe. During these years monks and nuns from Bec, Mont de Cats, and Chevetogne frequently came to stay and share the life of the cathedral. From 1987 to 1996 he was programme director at the St Theosevia Centre for Christian Spirituality in Oxford. As a freelance theologian with private means but no ambition, he was free to lecture and teach at many institutions in America and France.

His most important books include The Spirit and the Word (1963), The World is a Wedding (1978), The Dynamic of Tradition (1981), The Joy of all Creation (1984), Threshold of Light (1986), The Heart of Compassion (1989), and God's Presence Makes the World (1997). All are written with an attractive lucidity and effortless charm. His magisterial study of the Danish patriot and hymn-writer NFS Grundtvig (1997) is much admired.

A walking holiday in Wales led toa major influence on Donald's thinking and writing. In the work of poets such as Dafydd ap Gwilym, Thomas Traherne, Williams Pantycelyn, Ann Griffiths and D Gwenallt Jones he found the well-springs of Christian belief and "a deep, hidden joy" which he had long sought.

Having learnt to read Welsh, he wrote a percipient study of Ann Griffiths, the great 18th-century hymn-writer, for the "Writers of Wales" series (1976), returning to her work in The Furnace and the Fountain (1987); he also edited, with E Wyn James, a volume of her hymns and letters.

In his book Sensuous Glory (2000, co-written with D Densil Morgan) he went into detail about how he had come to appreciate the language, literature and culture of Wales: "Like most English people I grew up in almost total ignorance of the existence of Wales. Only in my thirties did I begin to discover that there was another people in the south of Britain with a language and a history of their own. While they were much less numerous than the English they certainly had inhabited this island which is both theirs and ours, considerably longer than we had."

The book is still the best introduction in English to the poetry of D Gwenallt Jones, whose spiritual odyssey from industrial south Wales to incarceration in Dartmoor as a conscientious objector, and then to a lectureship at Aberystwyth, from chapel to atheism and then from church to chapel again, he found fascinating.

A more wide-ranging view is to be found in Praise Above All (1991), in which he explored praise in the Welshpoetic tradition from the 9th century to the present. His purview extended to include such major names from the canon of modern Welsh literature as Bobi Jones, RS Thomas and Waldo Williams, who are shown as inheritors of a tradition that is coloured by the Bible and by prayer and worship. Among contemporary poets in whom he had an interest are Ruth Bidgood and Gwyneth Lewis.

Donald Allchin, a genial and gracious man, was particularly fond of Ynys Enlli, the island known in English as Bardsey, and Pennant Melangell, the church in Montgomeryshire associated with the princess Monacella, who became the patron saint of all small creatures; he wrote guides to both places. The last 16 years of his life were spent contentedly in Bangor, close to the hill country which he so greatly enjoyed and where he held an honorary professorship at the University. In 2006 he was awarded a Lambeth doctorate in divinity but in 2009, and in failing health, he left for Oxford, where he was to die.

Arthur Macdonald Allchin, priest and theologian: born London 20 April 1930; librarian, Pusey House (1960-69); residentiary canon, Canterbury (1973-87); programme director, St Theosevia Centre for Christian Spirituality (1987-96); died Oxford 23 December 2010.