KIEV, Ukraine -- Every Sunday, thousands of worshipers crowd into an arena here for a rollicking evangelical Christian service. A choir and rock band belt out gospel tunes in Russian.
People sing along and clap and shimmy in the aisles. They dash up to the stage for a chance to grab the microphone and declare how their new faith has changed their lives.
It is as if a Sunbelt megachurch had been transplanted to Kiev, birthplace of Slavic Orthodoxy, land of onion-domed cathedrals and incense-shrouded icons.
But the preacher at the podium has little if any connection to the United States. Could there be a more unlikely success story in the former Soviet Union than the Rev. Sunday Adelaja, an immigrant from Nigeria who has developed an ardent — and enormous — following across Ukraine?
From his start with a prayer group in a ramshackle apartment soon after the Soviet collapse two decades ago, Mr. Adelaja has built a vast religious organization under the banner of his church, Embassy of God.
He has become one of Ukraine’s best known public figures, advocating a Christianity that pairs evangelical tenets with an up-from-the-bootstraps philosophy found in religiously oriented self-help books. (Several of which Mr. Adelaja has published.)
He has throngs of admirers, but is also reviled by some in the Ukrainian establishment who resent a black man from Africa luring white Slavs away from their religious traditions.
The Ukrainian Orthodox Church calls him a cult leader, and law enforcement officials have repeatedly investigated him, once accusing him of involvement in a pyramid scheme. Around Kiev, it is not hard to find racial caricatures of him.
The Russian government, too, has taken offense, barring him from entering the country, though he has a growing number of adherents in Russia.
Mr. Adelaja said he believed that he was declared persona non grata because he was a staunch supporter of the Orange Revolution in Ukraine, the pro-Western uprising in 2004 that the Kremlin opposed.
Mr. Adelaja, who has a boisterous laugh and a relentlessly sunny personality, tries to brush aside the insults. He said his church’s popularity showed that Ukrainians were on a spiritual quest after having weathered the state-mandated atheism of the Soviet era.
He said that more than 100,000 people attended services regularly at the main arena in Kiev or his affiliates across Ukraine, which has a population of 46 million.
“I came to this country disadvantaged as a black person,” he said in an interview, adding that he was blistered with slurs and epithets. “But still, with all my disadvantages, with my accented Russian language, I went out and said, ‘Hey, this will help you.’ And people have responded to it.”
Mr. Adelaja, 43, arrived in the Soviet Union in 1986 as a college student, then stayed after the Soviet collapse in 1991, later moving to Kiev. His wife, Bose, is also Nigerian and often conducts services at the church.
They speak fluent Russian, which is the native language for many here and is understood by most speakers of Ukrainian, the country’s other main language.
Embassy of God has sprouted affiliates throughout the world, and Mr. Adelaja has been praised by some American evangelicals for bringing their brand of Christianity to the former Soviet Union.
In Ukraine, Embassy of God undertakes a wide array of charitable activities, feeding thousands of people a month at soup kitchens and running treatment centers for alcohol and drug addiction.
But it has also thrived because Mr. Adelaja has tapped into a desire of people in formerly Communist countries to learn entrepreneurial skills and make money.
Mr. Adelaja did not study in the United States, but says he has learned from the teachings of American pastors. His views sometimes reflect the so-called prosperity gospel — a belief among some strains of evangelical Christianity that God wants the faithful to attain material wealth.
On a recent Saturday night here, Mr. Adelaja conducted a seminar with a few dozen people in a church annex. Reading from an iPad, he recited passages from the Bible and discussed how Christian principles could assist in business.
Mr. Adelaja and a parishioner, Ishtvan Birov, 35, bantered about how to innovate in life, personally and professionally. The conversation veered from Jesus to Steve Jobs, the Apple chief executive, back to Jesus again.
“Apple takes a model and keeps improving on it,” Mr. Birov said.
Mr. Adelaja responded, “That is the principle of God — to always keep making it better.”
He added, “God is strategy, God is strategic thinking.”
After the seminar, Mr. Adelaja explained that in the post-Soviet era, Ukrainians at first had only one major choice, the Orthodox church. But he maintained that many were turned off by Orthodox services because they were conducted by solemn, bearded priests chanting complicated liturgical texts.
“We are always thinking, how can we make the Bible still relevant?” he said. “The same values, the same product. But not doing it in the Orthodox old style. I don’t want to go to a church where I am just standing there and don’t know what is going on. We must make it interesting. We must change the packaging. Not communicate it in a way that pushes them away, but draws them close.”
Mr. Adelaja has never sought Ukrainian citizenship because he said he did not want to raise suspicions that he was interested in obtaining political power.
Because he is not a citizen, the authorities could deport him at any time. But he said that they feared doing so because of a potential backlash from his many parishioners.
Prosecutors also seem reluctant to move forward on a 2009 criminal case against him, which alleges that he took part in a fraud scheme whose victims included his church members.
Mr. Adelaja said the charges amounted to a political vendetta, and the case did not appear to have diminished his standing here.
In the interview, Mr. Adelaja said he did not live a life of luxury. He said his parishioners were encouraged to donate 10 percent of their salaries to the church, though there is no requirement that they do so to attend services, and many do not.
Mr. Adelaja said that money goes toward the church’s activities, including plans for a new $50 million headquarters here. He earns a living largely from sales of his books, he said.
His opponents said whether or not he was exploiting parishioners financially, he was promoting false Christian ideals.
“His methodology, his Biblical views are twisted,” said Dmitri A. Rozet, who runs a Web site called Adelaja Watch. “He wants to use God for human benefit. That does not correspond to anything that Christians have believed for almost 2,000 years.”
Still, at services on a recent Sunday, many parishioners seemed enthralled.
“Before, I was depressed, and my life was a nightmare,” said Anna Vdovenko, 63. “Now, I am living. And it is all thanks to Pastor Sunday.”