NOW COMES Rev. Jerry Falwell, the Moral Majority's leader, to ask Congress to veto a new District law on sexual activities because it is, Mr. Falwell says, "perverted." He anticipates that some objection might be made to his request for Congress to intervene in local affairs, and he says that home rule does not include the right to legalize decadence. Mr. Falwell is being joined by some local supporters, including the Baptist Ministers' Conference.

The merits of the legislation that Rev. Falwell opposes need not be argued--again--here. It is enough to say that local attention to the bill resulted in trimming certain sections from it, notably a provision lowering the age of consent for teen- agers involved in sexual activity. As it stands now, the bill decriminalizes only homosexual acts and sodomy between consenting adults. This is what the city council and mayor approved, after much public outcry about the bill. Mr. Falwell is not shining a light on obscure legislation that lawmakers would sneak past District residents.

It is noteworthy that Mr. Falwell did not address his objections to the city council when it was considering the bill or to Mayor Barry before he signed it. Mr. Falwell's focus is on Congress. His interest in this legislation, he admitted, is based on the fear that it might be a model for other cities. That is why he has asked Congress to override the law by passing two other bills.

Mr. Falwell's views would have been appreciated before the city council. There are local residents who agree with him. Asking Congress to undo what locally elected officials have decided is best for the city, however, is to wreck the delicate balance of home rule. The D.C. government operates with a caution born of full knowledge that Congress can wipe out any local law or decision it finds undesirable. Congress has so acted before, mainly in cases it thought directly affected the federal interest. To have Congress begin taking action on a local matter now would make home rule a charade and would take away much of the city's limited claim to democratic rule. Congress, in its diplomatic way, should show Mr. Falwell the way to the District Building as it shows him and his proposal the way out.