NEW ORLEANS -- The Rev. Simon Ngugi, who has 13 children, is an Assemblies of God preacher in the Kenyan town of Mungaria, population 7,000, where cows mean not only milk for consumption and sale but also provide manure that is essential for farming.

But Ngugi, 38, sold his only cow for about $240 to help pay for his trip to the North American Congress on the Holy Spirit and World Evangelism here this week. His brother-in-law and his 200-member congregation provided the rest of the money he needed. The Congress itself gave him money for meals and lodging during the meeting, which concludes tomorrow.

"You see, brothers take care of brothers," Ngugi said of his good fortune.

Ngugi is one of about 35,000 charismatic Christians, Protestant and Catholic, gathered here for five days of rallies, seminars, prayer and praise services. The events and the enthusiasm they engender, leaders hope, will pave the way for a planned "decade of evangelism" in the 1990s, with the goal to convert half the world to this expression of Christianity by the turn of the century.

The attendance is significantly less than the 45,000 who assembled for a similar congress in Kansas City 10 years ago, a time when the charismatic renewal movement in this country was at its peak. And it's less than half the organizers' projection six months ago that 80,000 persons would turn out for the Congress here.

But that was before the Jim and Tammy Bakker scandal and the attention, much of it unfavorable, generated by Oral Roberts' pay-or-God-will-call-me-home fund-raising tactic. Both are in the charismatic pentecostal camp.

Congress Chairman Vinson Synan also blamed the attendance shortfall on the reluctance of people to spend the time and money on travel when so much pentecostal programming is available from television ministries.

The charismatic movement is a loosely structured mix of Protestants, Roman Catholics, Messianic (converted) Jews and Pentecostals. Most are evangelicals with a strong belief in the Bible and in the need for a born-again experience as a requirement for salvation.

All have experienced "baptism of the Holy Spirit," which they say is what Jesus' disciples experienced at the first Pentecost, which marked the beginning of the Christian church. And they believe that such a "baptism" bestows the "gifts of the Holy Spirit" such as speaking in tongues, prophecy, faith healing, working miracles and discerning evil spirits.

The Pentecostal movement surfaced around the turn of the century in the South, Midwest and in California. Its followers believed in the baptism of the Holy Spirit and its accompanying gifts.

For decades, Christians who held such beliefs left the mainline churches and joined the small, loosely organized Pentecostal denominations, or started their own churches.

But in the 1960s, a new movement of charismatics with the same emphasis on the Holy Spirit emerged in Catholicism and in mainline churches. Although some of the excesses of enthusiasm troubled church leaders, the charismatic movement was generally tolerated, and in some cases actively encouraged, by bishops and other leaders.

Synan said, "The movement continues growing, but it's gotten more denominational, more separate and regionalized . . . . Our main aim is to bring the groups in one place, then encourage them all to evangelize."

Missions researcher David Barrett, an Anglican priest from Africa who currently works for the Southern Baptist Convention missions agency, estimated that 200 million people worldwide consider themselves charismatics or Pentecostals, up from 75 million a decade ago.