Washington — Congress has two weeks to cut the budget; otherwise President Reagan threatens to close down nonessential federal activities again, as he did last week. Rarely have so many uncertainties beset the economy.
* Congress passed a stopgap measure to meet government expenses till Dec. 15; prospects are it will grumblingly extend this under presidential pressure.
* Mr. Reagan must submit a revised budget in January that takes account of (a) the current recession; (b) abandoned hopes for a budget balance by 1984; (c) prospects of a revived struggle with Congress over federal spending cuts, including where and how much.
* A similar battle over taxes.
* Twin tests of ''credibility'': one over Budget Director David A. Stockman himself, who first seemed to abandon, and then reembraced, the administration's supply-side package; and the other over Mr. Reagan's own triple goal - lower taxes, lower federal civilian spending, and higher defense spending.
Amid this confusion of opinion there were solid developments. The Commerce Department's monthly list of ''leading economic indicators'' dropped for the third consecutive month: 0.6 percent in August, 2.2 percent in September, and the latest - 1.8 percent in October. The figures indicated no that the end to current economic problems is still out of sight.
At the same time Treasury Secretary Donald T. Regan, over ABC's weekend television, argued that the current recession is being exaggerated by private economists. He reiterated the administration hope that recovery will come early next year.
Meanwhile, the President and his counselor, Edwin Meese III, in separate comments argued that Mr. Stockman's credibility has survived in Congress despite his recent questioning of the Reagan program. Stockman subsequently reaffirmed his faith.
The government's master file of ''leading economic indicators'' confirms that a recession is under way, with evidence that high interest rates are injuring housing, automobile, and other industries, while unemployment grows. Six of the 10 indicators were down.
In his interview in the Atlantic, Budget Director Stockman said the Kemp-Roth supply-side economic stimulus theory hasn't worked. He called it ''a Trojan horse'' maneuver to force down top tax rates for ''the wealthiest individuals and largest enterprises'' to carry through the ''trickle down'' theory.
Stockman later retracted this expression. Interviewed by ABC television, President Reagan defended both his economic recovery program and budget director. ''David Stockman was not the sinner. He was sinned against,'' he declared, adding that Stockman supposed his comments on the interview were ''totally off the record.''
At breakfast with reporters Nov. 30, Mr. Meese confirmed the administration hope that Mr. Stockman will not lose credibility with congressional economic leaders with whom he deals. Few in Washington are more conversant with budget details than he. It seems to be touch and go whether his authority can survive the strain of his uninhibited comments.