A Second World War veteran tells this story. He was in the front line, under bombardment, when he felt a tap on the shoulder and heard a voice saying, "Would you like a cup of tea?" It was a Salvation Army officer. George Gillan, the officer in charge of York House in Dublin, recounts this anecdote. It captures the mix of the comic and the heroic which has come to characterise the Salvation Army.

It first arrived in Ireland in 1888. The army now has four centres and a church in the Republic (all in Dublin), and four centres in Northern Ireland. However, its profile in the South remains surprisingly low. Gillan suggests it is gradually gaining recognition.

"People see that the Salvation Army is not just people who go around banging drums and playing trumpets. It's a practical religion."

York House is the oldest centre in Dublin - open for more than 50 years, it houses 92 men. "Some have been here for 20 years, some may come only for one night. To get accommodation in Dublin is very difficult. People recognise they must get to a place no later than six or seven o'clock, because after that all the places are taken."

Cedar House, a new centre in Marlborough Place, is very different. It caters for alcoholics, drug addicts, and the occasional psychiatric case. Men start to congregate around the doors as early as 4 p.m. There are young drug addicts and battered old alcoholics.

A series of security cameras monitor the street and gardai walk by regularly (drug dealers try and do business outside the centre). The doors remain locked until 6 p.m., then the men surge forward as they are admitted to a small holding bay. They are all interviewed briefly and asked to empty their pockets of any alcohol or drugs (all belongings can be reclaimed the following morning). The sign on the office wall states simply: no alcohol, no drugs, no violence.

Pat Archer, a Northern Catholic, runs the centre. "I say to them, `This is for you. This is your home.' I try to keep notices to a minimum because I don't have notices around my house." The building is immaculately clean and is made up mainly of private bedrooms. There's a 12-bed dormitory for bad cases (who they prefer to keep together). It has a goldfish bowl and a small bookshelf - paperbacks ranging from Beckett to Robert Ludlum. There's a copy of the Psalms beside every bed.

Perhaps because it's so new, Cedar house doesn't have that oppressive institutional feel. There isn't even a smell of disinfectant. There are recreation rooms upstairs, with a piano, an organ and a pool table.

All the Dublin centres are run with financial assistance from the Eastern Health Board and Dublin Corporation. Between them, the four centres have around 120 staff. Of these, only five are Salvationists - the rest are from other religious backgrounds. The Salvationist church in Dublin, based on Lower Abbey Street, has 30 members. Pat Archer is concerned to give the residents of Cedar House back some sense of dignity. "Quite recently they were all in the holding bay, and I said, `Right, gentlemen, I need to speak with you.' And they all slightly shrank. I said, `We've had a report from our cleaners, and they've reported to me how tidy the rooms are.' And you could actually see each man grow in stature."

Archer has a question she likes to ask new staff: if Christ were to arrive outside the centre some night, what would you do? Would you bring him to the top of the queue, or treat him like everyone else? "I don't allow them to answer, because they should understand that Christ is already in that queue. You can see Christ in every man waiting out there."