A statement released the other day on behalf of a number of church leaders calling for a ban on human genetic engineering rests on false assumptions, and, if followed, would increase the very danger it decries.

The "theological letter" explaining the clerics' position declares that "it will soon be possible to engineer and produce human beings by the same technological design principles as we now employ in our industrial processes." If such a capability were near at hand, one might excuse some of the letter's apocalyptic rhetoric, such as the claim that the technology poses "as serious a threat to the existence of the human species as the bomb itself."

But the ability to "engineer and produce human beings" will remain science fiction, not fact, for many years. The real danger is that broadside attacks that mix together many complex issues will diminish support for--or even lead to prohibitions on --those uses of genetic engineering techniques that are manifestly beneficial in treating and even curing diseases. There is no question that the new genetics offers the brightest hope for understanding and eventually controlling many debilitating and sometimes lethal conditions--from Tay-Sachs disease and sickle-cell anemia to cancer.

Sometimes when an urgent problem is being ignored, it may be justified to yell "Fire" just to get attention. But a false cry of fire is not needed in this case. Although the theological letter opens with the statement that "little or no debate has taken place" on human genetic engineering, the subject has actually been discussed intensively for more than a decade.

Indeed, the leaders of the Protestant, Catholic and Jewish organizations expressed concern to President Carter in June 1980 over the lack of government oversight in this field. Consequently, the President's Commission on Medical Ethics was asked to add this subject to its agenda.

After a series of public meetings on the subject, during which the views of religious spokesmen (along with scientists, physicians, philosophers, lawyers and members of the public) were considered, the commission issued its report last November--a report recently praised in the leading bioethics journal, The Hastings Center Report, as "always focused, astutely reasoned (and) polished."

The commission identified the potential problems in changing the genes people pass on to their offspring as one of the issues that deserve continued public scrutiny as the specific capabilities came closer to hand. The Hastings Report termed the commission's conclusions "specific, coherent in analysis and braced by a solid infrastructure of moral discourse."

Further public attention to the issues occurred when a House committee on science and technology held three days of widely reported hearings on human genetic engineering at the time the commission's report was released. The witnesses, who represented a broad spectrum of opinions and backgrounds, were virtually unanimous in supporting the suggestion that a commission be established to continue the oversight of genetic engineering begun by the president's commission. A bill to establish such a body was introduced by Rep. Albert Gore Jr. (D-Tenn.).

How much better if the church leaders had recognized that the public has already moved far beyond square one in the discussion of human genetic engineering and that the issues are far too complex for across-the-board prohibitions. If their real intention, as some of the signatories have since explained, was simply to encourage further discussion, how much more responsible it would have been to endorse the Gore proposal instead of calling on Congress to ban all gene alterations in the human germline.

An absolute ban on such changes would probably preclude any treatment for certain serious illnesses that affect many parts of the body or that occur very early in development because genetic alterations in these diseases would affect the germinal cells as well.

Do we want to ask those people who suffer the ill effects of the genetic lottery to bear the heavy (and sometimes lethal) effects of our unwillingness to find more finely tuned means of avoiding potential abuses of genetic alterations? Somehow, I expect a more compassionate response on the part of religious leaders.

The reason for their concern--as expressed by Jeremy Rifkin, who drafted the statement and obtained the signatures--is fear of the eugenic uses that might be made of the new technology. Ironically, by asking Congress to impose a ban, the signatories are taking away private control and involving the government directly in medical and reproductive decisions. Yet history shows us that past eugenic abuses all involved governmental power, often begun by well-meaning and "enlightened" people. This danger would not arise with a commission (such as the one proposed by Gore) that would ventilate and clarify the issue, not regulate personal choice.

Shouldn't we have more faith in the resiliency of our society-- and in the basic morality and common sense of our people--than to respond to what are still hypothetical problems with a federal ban?