Refreshed by the tranquility of rural Iowa, a jubilant John Paul II arrived in this teeming industrial city tonight to the greeting of Polish and Irish street bands, children bearing flowers, political and religious leaders and, as always, a harsh night wind blowing in from Lake Michigan

After a short welcome at O'Hare International Airport, the pope traveled into the center of America's largest Catholic community for a visit to Holy Name Cathedral. As his motorcade weaved through the city's neighborhoods, street banners and posters loomed from thousands of windows like a hall of mirrors reflecting his beaming face to infinity.

The pope had little contact with the people of Chicago in the few hours here before he laid his head to rest in Cardinal John Cody's Gothic mansion. But there will be a full day of events Friday, and even before he arrived, the pope had fostered a rare unity in a fractious Catholic community where mass is celebrated in more than a dozen languages.

Chicago wears its ethnic diversity on its sleeve, but by day's end the city's many voices had blended into a chorus heard everywhere: "Witamy"; "Bi- envenuto"; "Hey, John Paul, Gimme Five," "Welcome."

"Everybody wants a piece of the Polish pope," summed up a burley Polish machinist with a proud grin. He stood outside Five Holy Martyrs Church on Chicago's South Side, watching carpenters from the Polonia Construction Co. put the finishing touches on an altar where the pope will soon consecrate bread and wine.

The Polish community of Chicago, which is rooted in the north along Milwaukee Avenue, with branches along the South Side, is the largest in the world outside of Warsaw.

Friday at 8 a.m. in a parking lot renamed Five Holy Martyrs Field for the occasion, their moment will come. Chicago's Poles see themselves for once as first among equals. At his own request, the pope will deliver to them his personal message for all of Polish America.

Because of John Paul's remarkable openness to people throughout his career, many a Chicago Pole met him in Krakow or during his two previous visits to Chicago while he was still a cardinal.

The most recent was in 1976 when, in addition to doing church business, he took a boat ride on Lake Michigan and rode an elevator up to the 103rd story of the Sears Tower, to view the sweep of this mecca of materialism and technology that is the home base of McDonald's and Wrigley's Chewing Gum, and the site of the nation's first controlled nuclear reaction.

This visit has been different. All week beleagured priests, like sudden matinee idols, have struggled with jangling telephones, growing hordes of journalists and TV camera crewmen, and beseeching parishioners who had lost out in the lottery for tickets to the papal masses for the Polish community at Five Holy Martyrs and the general public on Grant Park.

"Father, my family got nothing. Nothing," a tall parishioner whispered urgently into the ear of Five Holy-Martyrs Bishop Alfred L. Abramowicz.

"I'll see what I can do," the bishop told him, moving straightbacked through the busy churchyard.

A white-haired priest murmured, "I came all the way from Arizona for the pope. This was my parish for 30 years. But now I'm just a number. There are 1,500 people on the waiting list."

A bit later, the bishop slipped the old priest a small envelope and patted him on the back.

The bishop, who is also executive director of the Catholic League of Poland, has met with John Paul II regularly since 1960. The future pope slept in the church rectory twice.

Many credit Abramowicz with "snaring" the pope on this visit. The bishop, however, insists this particular stop was completely the Vatican's choice.

Pope John Paul II will spend more time in Chicago than in any other city on his American tour, travel the farthest, and make the most appearances. Still he forced archdiocesan officials here to some tough choices. "We're disappointed because we were under consideration for a long time," said Father Dominic Carmon, of St. Elizabeth's Church, the oldest black church in Chicago. The pope will miss it by a few blocks. "But we understand there just wasn't enough time in his schedule."

Cardinal Cody, in a move last week to mollify black Catholics who felt slighted, rerouted the pope's motorcade briefly through a South Side black neighborhood.

The Hispanic contingent, one of the largest in the country outside the Southwest, is scheduled to receive only a five-minute stop. It will take place in the shadow of the Dan Ryan Expressway in a neighborhood so poor the parish children have had to make their welcoming banners out of bedsheets.

Church officials have put themselves through contortions to include at least one representative of every kind of human being -- by race, sex, ethnicity, handicap, age, creed and economic class -- in some role during the pope's 38 hours here.

"No other city in the country is as ethnically aware," said one veteran Chicago political pundit. "Newcomers are amazed at the way the newspapers openly discuss ethnic and religious policies."

Several Democratic aldermen and candidates for office here this week distributed souvenir programs and posters for the papal visit.

Alderman Roman Pucinski, once a congressman, traced the pope's route through his ward, past his office, and urged constituents to "Come early! See the pope in person! Receive the papal blessing! Bring your whole family!"

Though they make up what is by far the largest Catholic ethnic group here, the Poles have traditionally taken a back seat politically, as have most others, to the smaller but potent Irish Catholic contingent. It included the late mayor Richard J. Daley and now the current mayor, Jane Byrne.

The cross-allegiances between the Catholic Church and Chicago's Democratic Party here were always clear.

During Daley's 20 years as mayor, the story goes, the surest way to an appointment with him was to get your priest to escort you to city hall. It was said that Daley would "never refuse a priest."

Some recall the day in 1955, when Daley was running for his first term, that South Side parochial school students brought home letters from their nuns, touting the virtues of Daley and mentioning that his Republican opponent was a divorced man.

"The church didn't exactly authorize it," said a local political operative, "but they didn't stop it. Today, they'd never risk it."

Equal opportunity lawsuits and changing times generally have shrunk the Irish Catholic share of top city patronage jobs, he said. Though the archdiocese still has a lobbyist in Springfield, the state capital, the church is no longer seen as the distinct factor in local politics that it once was.

Besides galvanizing the public, the pope's visit has brought at least a temporary lull in the hostilities that have embroiled the church leadership and, some say, crippled the archdiocese.

Dissatisfaction over Cardinal Cody's leadership, voiced by laity as well as clergy, has, for some Catholics, transformed the archdioceses into a symbol of what ails the church in America. The controversy centers around the manner of the feisty, reclusive 70-year-old prelate.

Liberal and conservative critics, mostly dissident priests, have called for his dismissal. The cardinal, like his rambling, church-owned mansion, is a stodgy relic of another era, they say.

They claim Cody's authoritarian ways are destructive in this age of reform and social change.

In fact, John Paul and several of his predecessors have tried to ease Cody from his post, according to priest-author Andrew Greeley, a leading critic of Cody.

Cody, a heavyset man with a pink and kindly face, has angrily denied this.

In one incident critics say is typical of Cody's heavy-handedness, parishioners booed out loud in church one Sunday when they learned that Cody had decided, for reasons of economy, to shut their South Side church immediately. They took their case to court, and also appealed to the Vatican. The parishioners now run the church without archdiocesan support, pending resolution of the appeal.

Cody's defenders point to his accomplishments as a financial manager and administrator and to his efforts to reach out to blacks and Hispanics.

Up to now, at least, Cody has made effective use of his strong ties to Polish Catholics (he has extended financial aid to the church in Poland) as well as Vatican allies to save his position, according to Greeley and others.

Meanwhile, says Sun-Times religion editor Roy Larsen, many priests have become demoralized, and the archdiocese has turned "gray and dispirited."

But this week the critics are silent.

The Chicago Defender, "the world's largest black newspaper," praised Cody for his "tireless efforts to eradicate racial segregation" and his support of the Rev. Martin Luther King Jr.

And the Rev. Joe O'Brien, who leads Cody's opposition, told reporters that it would be both "impolite and impolitic" for him to say anything critical of the cardinal while the pope is here.

Still, many are hoping that the pope will send a clear signal of his intentions for Cody, Larsen said, and end the speculation and drift once and for all.