The Rev. Richard Greene is building an ark.

To be more precise, the 41-year-old Church of the Brethren pastor is rebuilding, on a Western Maryland hillside, what he believes is a model of Noah's ark from the Bible.

Until the day of judgment comes, which Greene is convinced could be any day now, the ark will be used as the meeting house of the Frostburg Church of the Brethren, of which Greene as been pastor for the last three years.

The 450-foot-long building may also house a Christian school, or a community center or even a clinic. It all depends on what God tells Greene to do with it.

For that is the reason Greene says he is building the ark - because God told him to.

The whole thing started conventionally enough. The little congregation was outgrowing its old Brethren Church building so the members bought 3 acres of farmland on the edge of town. That was when Greene's vision, or "night visitations," as he calls them, began.

Night after night for three months it was the same thing, the preacher recalls. Scene one: old Noah, straight out of the Old Testment Book of Genesis, preaching to scornful people and telling them to repent. Scene two: Noah, hammer and saw in hand, building the great ark with which he and his family and the animals would survive the great flood God sent to destroy the unrepentent and their wicked ways.

"It was a real, as clear to me as I see you sitting there," Greene said to a visitor, sitting across the green-and-white, crochet-covered kitchen table.

"I'd wake up in the morning and pray about it, "cause it was repeated night after night, always the same thing," he recalled.

Then one day while browsing in a Christian book store, Greene picked up a book by a man who has been part of an expedition to search for the remains of the original ark. The book contained a drawing of what Noah's vessel was thought to look like.

"When I opened up that book I almost fell to the floor," he said. "The spirit of the Lord came down on me because that picture was almost exactly what I had seen in my nightly visitations."

Convinced that this was one more sign that God did indeed expect him to rebuild Noah's ark. Greene "yielded," and the following Sunday told his congregation about the visions and the destiny Greene believed God had in mind for them.

Divine visitations not withstanding the pastor was aware that there might be some problem in selling a congregation of some 100 practical-minded farmers on undertaking a million-dollar building project. So he asked God to "sent an artist to my door" who would sketch the building that appeared in Greene's visions.

He promised his congregation that the detailed sketches would be ready for them within three weeks. "What I did, I gave God three weeks to send somebody (an artist) to my door," recalled Greene, who has a somewhat more casual approach to the almighty than his Old Testamony prototype.

Within a week-and-a-half, the prayed-for artist appeared - just one more sign, according to Greene, that the whole enterprise was part of divine planning.

When Greene presented the sketches, which were actually preliminary architectural drawings, to the members of the congregation, they agreed, after only 10 minutes of discussion, Greene recalls, to go ahead with the project. To Greene that was "the greatest miracle of all," he said, recalling that only a couple years earlier the church had voted down spendig $2,000 for new pews and lights.

Once under way, the progress of the ark has been just one miracle after another, according to Greene. None of them surprised him, though, since "God has revealed in the vision that people of all faiths around the world would contribute with their monies, talents and materials."

For instance, there was the retired farmer from whom the church bought the land. The original 3 acres, purchased when they were still thinking in terms of a conventional church, proved to be too small an area for an ark, which to be authentic, they decided, must be 450 feet long.

Greene went bact to the crusty old farmer, who had been on record as saying he would "never sell another inch" of his land. On the way to the interview, "God told me what to say to him," Greene recalled.

"It told him, "I know you said you'd never sell another inch of your land. But Godld told me to ask you if you would donate abother arcre to Him for the ark," Greene recounted. He got the land.

From bolts to bulldozers, an assortment of donated goods and services has found its way to the muddy hillside where the ark is under construction. In Green's view, each item was went there by God and is further conformation of divine blessings on the project.

His superiors in his denomination take a less benevolent view. The Church of the Brethren is one of the historic peace churches, with a strong tradition of social concern.

Church officials are "somewhat embarrassed" by Greene and his ark, addmits the Rev. Earl Fike Jr., the demonination's national executive for parish ministries, at its offices in Elgin, III. Fike explained that the spending of well over $1 million to produce a model of Noah's ark represents a priority "off to one side of any kind of denominational thinking."

But within the Church of the Brethren, Fike continued, local congregations are autonomous so "there's really nothing the denomination can do as long as they're not promoting something completely in conflict with the Gospel."

In national church circles, Geene and his ark have become the butt of some church jokes. At a recent meeting to discuss aid to victims of last summer's disastrous flood, one person proposed asking Greene to move his operations to Johnstonwn, Pa.

According to Greene, the building of the ark is one more fulfillment of the biblical prophecies that he sees as foretelling the end of the world. He cites verse 37 of the 24th chapter of the Book of Matthew in the New Testament: "But as the days of Noah were, so shall also the coming of the Son of Man be."

"We are building the ark in order to fulfill that verse," he said.

He believes the ark, which will be visible from U. S. Rte. 48, will also serve a missionary purpose.

"People who wouldn't be caught dead in a church - out of curiosity, they'll come to see what Noah's ark was like and we'll share Christ with them," he explained.

He misses no opportunity to "share Christ" with whomever he encounters. Already, he says, with the ark no more than a large hold in the ground, it has led "over 1,000 people to make decisions for Christ."

Like millions of fundamentalist Christians today, Greene looks for the end of the world soon and the physical return of Jesus Christ. "It could be tomorrow, it could be 10 years, it could be 100 years," he said. "We may never get the ark built before he comes - but in that vision I saw it completed," he adds.

When that time comes, these Chistians believe, only those who profess faith in Christ will be saved.

Greene justifies his tireless efforts on behalf of the ark, which he sees as helping to fulfill the prophecies of the final days, with a heads-I-win, tails-you-lose philosophy. "If I'm right, look at all I've gained. If they (the unbelievers) are wrong, look at all they've lost."