Torrents of sacred and profane rhetoric threaten to engulf the dying man inAidan Mathews's new play. But the playwright has a clear picture of suffering and redemption, partly informed by his work as a religious broadcast producer. He talks to Helen Meany

Death-bed scenes in opera are renowned for their sudden musical flourishes and Aidan Mathews seems to have taken his cue from them. In his new play, Communion, the pivotal character, Jordan, is a young man terminally ill with a brain tumour. Engulfed in torrents of rhetoric, both sacred and profane, he almost disappears amid the hot air that fills his bedroom. His brother Marcus, who suffers from manic depression, delivers the most exuberant arias, but all the other characters - his mother, a friendly Methodist minister, a Catholic priest and his brother's girlfriend - also test their eloquence and wit by his bedside.

Fraternal rivalry, maternal jealousy and filial resentment are some of the themes of the play, set in the present in a comfortable middle-class Dublin household. The two kinds of illness suffered by the brothers - one physical, the other mental - become the locus of an extended dramatic exploration of the nature of religious faith, intensified by the imminence of Jordan's death. Each of the characters has a profound need for faith, even if, like Marcus, they comically mock themselves for it.

With its fluctuations between the absurd, the grotesque and the metaphysical, the play's style is characteristic Mathews; it's 12 years since this 46-year-old radio producer has written for the stage, but his playfully serious voice is immediately recognisable from his poetry as well as his short story collections, Adventures in a Bathyscope, Lipstick on the Host and his novel, Muesli at Midnight. His years of producing radio drama have been an education in craft, he says. "Writing for the voice only is a very subtle form. Its sureness and spareness is very pleasing."

His return to the theatre from his niche in RTÉ was spurred by the Abbey's artistic director, Ben Barnes who directed his play Exit-Entrance in 1990 and who commissioned this new work, which is directed by Martin Drury. The subject matter arose from Mathews's preoccupation with faith. In his secondary role as producer of religious broadcasts for RTÉ he has encountered many varieties of religious belief and has "gratefully taken anything of value from any tradition".

"Death interests me increasingly," he says, in a conspiratorial whisper. "Of course it brings narrative closure to a story and constitutes it as a text. On another level I'm concerned with how death abolishes meaning - everything becomes meaningless - while at the same time it confers meaning: through the experience of another person's death you discover pity. I wanted to write about the awful watchful witness of seeing someone you love die."

OR someone you hate. For Marcus, the death of his brother Jordan is something he wished for, envied and dreaded. "It's hard to part with one's enemies", Mathews smiles, "they infuse one's life with meaning." Marcus feels jealousy and resentment of Jordan's illness which has "cultural prestige", as Mathews puts it, while his own mental illness is terrifying. "At the end of the play Marcus no longer has an enemy and that's a dispossession too." It is also an opportunity for some change in him; as his adolescent rantings subside there's a movement towards reconciliation with his mother, and some inklings of compassion.

"Yes. I see the transcendence in tragedy and vice versa," Mathews says. "I used to think in binary pairs but now I have the awareness common to all kinds of mystical traditions: that there is a subtle relationship between suffering and redemption. I do think things can be redeemed." This theme recurs in conversation with Mathews: he stresses the possibility for growth that resides in pain, vulnerability and adversity.

A striking feature of the play is its sympathetic and sensitive portrait of the Catholic priest, Father Anthony, who visits Jordan regularly to give him communion, "to tell stories about Jesus the Jew" and "to share food", as he puts it simply. At one point everyone participates in the sacrament which has a celebratory tone, as Anthony stresses the loving nature of the God he believes in. "We are more than we imagine. We are the children of the spirit of the God of Jesus of Nazareth. We may not have time for God. God believes in us. We may not love God. God adores us. And, insofar as we love one another, especially those we cannot bring ourselves to like, then we are loving God face to face."

In other ways too the play celebrates the distinctive legacy of the kind of privileged Catholic education that is almost extinct. The two clever, competitive brothers have a weakness for theological dispute, bad puns, and Latinisms, gleefully blending scatology and eschatology in ways that Stephen Daedalus would appreciate. A Jesuit-educated doctor's son, like the brothers in the play, Mathews remembers his own Catholic boyhood in south Dublin with happiness and affection. As well as being taught by priests, he served Latin Mass in the house of a priest who was kind and paternal. "I have always been a Christian," he says, "tradition is important to me." Yet, as a student in his 20s he felt Christianity had lost the intellectual argument and he became an "arterial sclerotic", as he puts it.

His post-graduate studies in California in the 1970s under the French theologian Rene Girard helped him to reconcile his faith with his intellect. "In Girard and some of his peers I felt a marvellous reclarification had been undertaken. They opened the Hebrew bible and the gospels to fresh readings and readers. Girard offered me a reading of the atonement theories of Christianity that was rational and reasonable."

His criticisms are reserved for the institution of the Catholic Church rather than individuals. The Church's "gluttonous desire for power" is misguided, he says, "authority does not come from power. The first mandate of Christianity is to stand on the side of the victim. The Passion narrative is a threnody for the victim. The superstructure of the Church authorities has always had difficulty accepting how flawed and fragile the community is. It is a community of persons who try to make progress, who are, by definition, not Christ. In prayer and in praxis the Jewish story and the Christian story speak to our weaknesses and our faults."

He views the current crisis in the Catholic Church as an opportunity for renewal. "This is a hopeful time," he stresses, in which change is possible. He contrasts it with the Ireland of the 1950s. "The world I inhabited as a child was static and selfish, but people are now more sensitised, there is progress. Service is much more important than sacraments - it's more important that the feet be washed and the bread be broken - and more people than ever are doing this."

His forays around the country broadcasting religious services have brought him into contact with many parish priests. "I do feel for the clergy. In the main, parish clergy are quite lonely and isolated, living apart, in solitariness. When we live alone we can become introverted, preoccupied, without companionship, without children or the largeness of family life."

He recognises the possibility of this isolation and disconnection in himself. "I have hope - but then, I have children. I inhale their confidence and curiosity and restlessness. Otherwise, I'd waste away."

Communion opens at the Peacock tonight at 8.15 p.m. Booking on tel: 01-8787222