In sharp contrast to the upbeat inauguration four years ago, Montgomery County Executive Charles W. Gilchrist and seven Democratic council members took office yesterday acknowledging that relatively affluent Montgomery faces hard times for the next four years.

The inaugural ceremony itself at Rockville's Richard Montgomery High School was resplendent with music from the Damascus High School Band, a presentation by the county's police color guard, and Broadway selections from "The Show Stoppers," a Potomac high school chorus.

Clerk of the Circuit Court Howard M. Smith delivered the oath of office to Gilchrist and to council members David L. Scull, Esther P. Gelman, Rose Crenca, Scott Fosler, Michael Gudis, Neal Potter, and William E. Hanna Jr., the only newcomer to the council. They all signed the official county roll and received cheers from the hundreds of spectators packed into the auditorium.

Yet the speeches from Gilchrist and Scull were more downbeat than the day's events portended. They spoke of a county relatively well off (in 1980, household income averaged $39,800), but which sees its rich tradition of liberal programs and its reputation for economic security threatened by shrinking resources, potential polarization among segments of the community, and insecurity caused by unemployment, layoffs, and high housing costs.

Gilchrist summarized the tone of his remarks by citing a rather bleak quotation from Ralph Waldo Emerson, who said, "Great men and great nations have not been boasters and buffoons, but perceivers of the terror of life and have manned themselves to face it."

Yesterday's downbeat tone differed from the inaugural ceremony four years ago, when Gilchrist, standing on the same stage at Richard Montgomery High School, opened his new administration on an upbeat, optimistic note. On that day, he quoted Thomas Wolfe as saying "the true fulfillment of our spirit is yet to come." Gilchrist promised then "that the tone of the new administration will differ sharply" from that of his Republican predecessor, James P. Gleason, who had become increasingly critical of government's inability to solve problems.

Gilchrist yesterday conceded that his bleak assessment "may not seem to provide a basis for hope and progress." But he said he was still optimistic because of the county's reservoir of talent, citing the stepped-up involvement of the private sector in aiding the working poor and indigent who need legal services. He also praised the vision of county planners to create a corridor of high-technology, "smokeless" industries as the staple of Montgomery's economic development. "Today, that is a reality," Gilchrist said.

Scull, speaking for the council, stressed the theme of fiscal restraint. "The coming years may present a really needed opportunity -- a breathing space -- for progressive people to take stock of what they've built . . . to look it over carefully, change or eliminate where needed, and generally make the whole thing work as well as possible."