PASSING THE BUDGET is turning into the most abrasively difficult and divisive of congressional exercises. Last fall the second budget resolution was enacted only belatedly and untidily. This year the budget process is turning out to be even harder. For the Democrats, it forces the most painful of choices -- between unemployment and inflation, between defense and social services. There is now a substantial rebellion under way among some of the Democrats in the House, mostly urban liberals, against the level of defense spending demanded by the Senate.

At the same time, the budget presents the House Republicans with a crisis of their own. In the House, the Republicans have been happily exercising the opposition's prerogative of voting as a bloc against the budget resolutions. But this time it's a resolution that would balance the budget, that would raise the share for defense -- and that won't pass without Republican help. Indecision among the Republicans is being aggravated by the forthcoming retirement of John J. Rhodes as the party's floor leader and the maneuvering of the candidates to succeed him.

The budget is now approaching the final votes on the first resolution -- the one that is passed in the spring to serve as a guide to the committees as they work on the spending legislation for the fiscal year starting next October. Both House and Senate passed versions that called for small surpluses. But the Senate's versions gave more to the Defense Department, and the compromise emerging from the conference resembles that parent. Unlike the second resolution that Congress will take up in the fall, this one is not legally binding. But it is the one that will be in the book, and in people's minds, when the presidential nomination conventions are held and the campaign begins.

This first resolution is, in general terms, a reasonable and responsible price of work. Balancing this budget was not optional. After all of the congressional and presidential promises to do it, a failure now would have looked like another inflationary cave-in. That would have reawakened the financial panic that drove interest rates up to 20 percent in March. As for defense, it has been clear for some time that substantial increases are necessary.

There's no question that some of the cuts will hurt. But building highways is not, at the moment, as urgent as strengthening the Navy. About 50,000 subsidized public services jobs will disappear -- that's roughly one out of four of them -- but the similarly subsidized jobs for the low-income, long-term unemployed won't be reduced. There will be less money for mass transit, education and the postal service. Those are all important. But these cuts don't quite amount to a wholesale trashing of the nation's social commitments, or an indiscriminate abandonment of the poor.

One large issue is whether Congress is actually capable of finishing the job. For many years it left those hard choices to the White House. Now it has resumed its constitutional duty, and the country has benefited. But this year's test is unusually severe. The Senate will probably accept this first resolution without great difficulty. Whether it can be pushed through the House is another matter. The House vote is scheduled for Thursday.