The Rev. George Clements of Chicago has little time for schemes for reorganizing the society, or overhauling its basic structures, or redistributing its wealth.

This 50-year-old Catholic priest is a practical man, whose notion of Christian service is to grab a piece of the problem and go to work.

Thus it is that he has been touring the country, urging black churches to help eradicate what he considers a particular disgrace: the institutionalization of perhaps 100,000 black children who are available for adoption.

For more than two years now, he has been selling his "one church, one child" approach, urging every black congregation to see to it that at least one of its member families adopts at least one black child. Typically, he started his program by defying the tradition of his own church and adopting a 12-year-old boy who had spent most of his life in institutions after being abandoned as an infant.

At first, he urged entire congregations to agree to give financial help to the adopting families, but he's not pushing that line any more. "It's just not necessary," he told me the other day. "The fact is that there really are enough homes for these children. It's just a matter of matching them up."

So far, he said, 194 churches have bought into his program. So has the Reagan administration. "The president heard about what we were doing and sent Dorcas Hardy (assistant secretary of health and human services) out to take a look." As a result of that visit, HHS has provided a grant of $150,000 to help Clements spread his idea.

The money, to be used for staff, transportation and other expenses, came just in the nick of time, he said. "I was doing things on a shoestring and at one point found myself in $10,000 debt, just from traveling around to various cities. It's very expensive. In fact, we had to hold a benefit in Chicago to get me out of debt."

He'd gladly do it again, he said. "I just get tired of people talking about problems and not really doing anything. It can be very frustrating."

It was just this sort of frustration that led him, a few weeks ago, to tell members of his Holy Angels congregation that he didn't want them worshiping in his church unless they were registered to vote.

"The cold fact is that we are never going to be given respect as a people until we stand up for ourselves," he told his startled parishioners. "Men and women, black and white, have died to earn us the right to vote. The blood of these martyrs is on the hands of those lazy, shiftless ingrates who refuse to even get a voter-registration card."

He repeated the message to the parents of the 1,400 pupils attending the Holy Angels elementary school. Either they would register, he said, or their children would be expelled. A thousand parents subsequently registered.

"I did it because I got tired of talking, talking, talking about registration and decided to try to do something to make them listen," he told me.

They listened. Indeed the voter- registration campaign spread city-wide, boosted by a $50,000 contribution from the Soft Sheen hair products people. According to Michael Lavelle, chairman of Chicago's Board of Elections Commissioners, well over 130,000 new voters were added to the rolls on the special Oct. 5 registration day.

"I can't tell you how many were added as a result of the campaign," he said, "but I can tell you this: our preliminary figures show an average of 3,000 new registrants per black ward, 2,000 per white ward. That's a complete reverse of the normal trend, in which white registrations usually far outstrip black."

But the adoption program remains Clements' pet project: "I am satisfied that the major reason these children aren't being adopted is not because they aren't wanted but because of the burdensome rules and regulations that hamper adoptions, making it particularly difficult for couples in one state to adopt children from another."

He is calling for federal legislation to "put a halt to this insanity of penalizing a homeless child because he happens to live in an 'unenlightened' state.

But while a sympathetic Congress could help, Clements says black people have to get busy doing some things for themselves: "How can we just can sit back and wait and still talk about black pride and self-respect?"