WASHINGTON — When Congress authorized the creation of a national spiritual home in 1893, it envisioned Washington National Cathedral as a setting for presidential funerals, sermons by the likes of the Rev. Martin Luther King Jr., and spiritual services for epic national events like Newtown and Sept. 11.

But tai chi and yoga mats?

Seeking to modernize the historic institution’s mission and heighten its public profile, the cathedral’s leaders recently removed the thousands of chairs that normally fill its 10-story, Gothic worship area for a week of unconventional events in a suddenly transformed empty but dramatic space.

On Monday night, the nave was filled with dozens of people in socks after a lesson by a tai chi master with a silver sword. On Wednesday, a chorus will perform an unusual 40-part song while walking across the marble floor (cathedral officials call this “extreme polyphony”). On Friday, the soaring space will be open for an all-night vigil and be stocked with yoga mats and meditation cushions.

As mellow as it all sounds, the week-long public program – “Seeing Deeper” – is part of a highly orchestrated drive by the nation’s second-largest cathedral to remake itself and survive in an era when religious institutions are struggling. And what’s more institutional than a huge cathedral?

Washington National Cathedral, one of the Episcopal Church’s three major U.S. cathedrals, was already forced to halve its $27 million budget in the mid-2000s because of falling revenue before an earthquake in 2011 caused damage now tallying an additional $26 million.

Although it is now in the black, it must raise its roughly $13 million annual operating budget as well as the remaining $19 million for earthquake repairs.

About 65 percent of the revenue that funds Washington National Cathedral’s annual budget comes from donations; the rest comes from the endowment in addition to earned income from concerts, tourism and programming.

This month, for the first time, cathedral officials began charging a $10 admission fee for walk-up tourists to help fill the gap created by the decline in donations.

By making better use of the cathedral as a public space, officials hope to significantly boost large individual and corporate donations – with a long-term eye toward increasing the endowment.

“I think our future, in terms of funding the cathedral, is attracting major donors, like all big cultural institutions,” said the Very Rev. Gary Hall, the cathedral’s dean since late 2012. “And major donors are interested in innovative, transformative stuff, not just maintaining a building to be a tourist attraction.”

Experts say cathedrals across Europe and America have had to remake themselves as religious affiliation has become much looser and financial models built on membership have broken down.