When the Rev. John Johnson entered Washington Baptist Seminary in 1965, an instructor offered this advice: "There are three things a minister needs: a good wife, good transportation and a good government job."

In some seminaries his advice might have been taken as a joke, but Johnson and his fellow seminarians never raised an eyebrow. They already knew the economic facts of life for some ministries.

The old days of log churches and brush-arbor sheds, when Protestant clergy sandwiched their ministry between long hours on the farm or at the forge, may be long gone. But the age of the bi-vocational minister is far from over.

Two-career ministers are most common among Baptists -- particularly black Baptists -- and to a lesser extent among Methodists and non-mainline churches, especially those in rural areas or newly formed, according to church officials. But nearly all denominations have clergy who are employed outside their churches. Many work in church-related jobs such as teaching or broadcasting religious messages.

Statistics are sketchy, except in the case of the Southern Baptist Convention, the largest Protestant denomination, which has followed the trend closely because it affects so many of its ministers.

As many as one-third of the approximately 35,000 Southern Baptist ministers in the United States are bivocational, according to the Rev. Dr. William Cumbie, executive director of the Mount Vernon Baptist Association.

Their numbers increased by 4.5 percent between 1976 and 1980 as inflation forced some congregations to switch from full-time pastors, according to a report compiled by the late Rev. J. T. Burdine, a longtime researcher of the subject for the church.

In the Washington suburbs, about 10 percent of Southern Baptist ministers have other jobs, according to Cumbie. In the city itself, church figures estimate about 50 percent of black Baptist hold other jobs.

"Most black Baptist ministers work full time [in outside jobs] until they retire," said Johnson, a computer aide for the D.C. Police Department, pastor of St. John Baptist Church in Alexandria and president of the Alexandria Baptist Ministers Conference. "They have to because they receive such small salaries from their churches" since the members are so poor themselves.

Locally, ministers work in every sector of the work force. They're executives, clerks, laborers, police officers, auto mechanics, truckers, short-order cooks, cabbies and politicians. One local minister said he knows of a pastor who, unbeknownst to his congregation, moonlights as a bartender.

Often their evenings and weekends are crammed with counseling sessions and meetings. Some perform funerals and crisis counseling on their vacations and other leave time.

Most, like the Rev. Freddie Brown, say they work out of economic necessity.

"Most of my congregation is blue-collar and many are retired and can't support the church," said Brown, 39, a member of the Uniformed Division of the Secret Service and pastor of Mount Olive Baptist Church in Centreville, Va.

In other instances, the minister might have to work because, "When you're trying to get a church up and start it off the ground, there's a lot of sacrifice involved, especially in the Baptist church," said the Rev. Bernard Reid, pastor of Johenning Baptist Church in the District.

Working ministers "can do an adequate job but it would be a better job if they weren't working," said Reid, who retired from the federal government two years ago but continues his pastorate. "Once membership gets up to 300 or 400, you need to be there. There are so many little heartaches and problems a minister has to deal with. He doesn't have to be busy all the time, but just be there."

The Rev. Guy H. Johnson, on the other hand, said he and his congregation prefer the bi-vocational status.

"I have an ideal working arrangement right now," said Johnson, 47, pastor of two United Methodist churches near Gaithersburg and a 27-year employ of the maintenance department of the National Instutites of Health.

"I think I can give them the quality of work that they need in counseling and personal involvement," Johnson said. "I don't just stand on the outside and look in." Johnson attends church meetings three nights a week and schedules counseling sessions every night, in addition to the standard duties of Sunday services, funerals and the like.

"Realistically I don't have to work outside the parish.But I would be foolish to give up that government retirement in seven years," he said.

Some local ministers call clergy who draw two full-time salaries "double dippers" or "fat cats." Johnson, aware of such criticism, said, "It's not one of those things people like to talk about. A lot of people think of a working pastor as a putdown. But it isn't.

"It takes a very strong and dedicated person to take their life and extend it beyond the normal pattern -- not just eight hours a day and that's it," said Johnson . "I think it builds character."

Johnson said his double vocation leaves him with no free time. "But I love it. I feel I'm giving a service to the community." f

Johnson said his job doesn't interfere with hid day-to-day pastoral duties because his supervisor is flexible, letting him take leave time during church crises.

The Rev. Lonnie Salyers is not as pleased with his situation. Working both inside and outside the church "is not a good thing," he said. "It takes up all your free time."

"I feel every church needs a full-time pastor to do the job right. You don't get to do the visiting to the sick. You can't be there every time they really need you. You have obligations to your job that you have to fulfill."

In addition to working as pastor at Yorkshire Free Will Baptist Church in Manassas, Saylers is a locomotive inspector for Fruit Growers Express Co., a shipping firm.

Saylers, 42, who said he is paid $100 a month in expenses for his work at the church, wants dearly to be full time with his church."We've been talking for some time about how the church needs a full-time minister. It's in the works," he said. "But how long it will take is another question."

Besides pastoring at church and working 40 hours at another job, many second-job ministers function as unofficial chaplains at their workplaces.

"I visit my coworkers' families at hospitals and discuss problems," said the Rev. Ronald Winters, pastor of Shiloh Baptist Church in McLean and special assistant for military and veterans affairs to Sen. Harrison Williams (D-N.J.) On occasion he has performed weddings for coworkers.

Winters, referred to in his office as "Rev," said his congregation is happy and growing: "People are coming from far and near."

Another minister, the Rev. Dovey Rountree, an attorney specializing in murder defenses, feels her work outside the pulpit is also a calling.

When not in court, Roundtree, 67, can be found preaching at Campbell African Methodist Episcopal Church in Southeast Washington, where she is assistant minister. She also serves as general counsel for the AME church and is a senior partner in the law firm of Rountree, Knox, Hunter and Parker.

Combining these careers results in self-neglect, said Roundtree. "I need to go to the beauty shop and it's right up the street but I think there are more important things than a hairdo."

Working outside the church has some advantages, according to many ministers."They know what it is to have a nasty supervisor or to be trapped in a government routine or be passed over for a promotion," said one.

"I think a pastor who has worked has an easier time talking to people in the labor force," said Saylers. "It's a lot easier to help someone if you have done it yourself."

And there can be some other advantages, as Brown, the uniformed Secret Service man, can attest. He has used his fomer position as night guard at the Oval Office to persuade several senators and representatives to speak at his church.

But despite any such advantages, some ministers such as Brown continue to work at gaining full-time status."I've told them all along that I'n not planning on working two jobs all my life. I've had several full-time offers. But I'm being patient. Every so often the subject comes up at church. This may be the year."