The story of Delirious? is one of archetypal rock lore, more or less.

Insert the proper set of names and a few of the particulars in the five-man rock band's ascent in the pantheon of pop stardom, and you find five ordinary guys who started a part-time band that became a bit bigger than they'd anticipated.

Quite a bit.

Delirious?, which performs at The National on Saturday, is known to millions worldwide as the band that wrote, recorded and carried to the world the modern church classic "I Could Sing of Your Love Forever."

A celestially gorgeous pop/rock ballad, the song -- like classic hymns of centuries past -- has made its way into the contemporary church canon, gradually transcending creator-specific associations.

It also has cemented the tag of "contemporary Christian music" -- CCM -- to a band that would, perhaps, be more at home with a somewhat broader classification.

Rather than bothering with rancor over minor matters of genre definition, Delirious?, on its latest release, "Kingdom of Comfort," uses its platform and prestige to push itself and others out of any delusional comfort zones that success and relative prosperity might accord them.

A recent tour of India, playing almost entirely to the country's upper echelons, left the band rattled and determined to bring its faith to bear in very visible, tangible ways.

"Being a 'rock star' is confusing enough," said the band's bassist, Jon Thatcher, by phone from England. "Being a 'rock star' in India really messed us up. There is no way to put it in perspective.

"We're trying, in the lyrics of these songs, to make people aware of situations we ourselves weren't aware of. We can also do that with money. We can do it with time invested -- hands-on -- in the lives of hurting people."

The core of Delirious? formed in the early 1990s in Littlehampton, England, a 25,000-person spot-on-the-map on the country's southern shore. The band had no loftier a mission than to provide some worthwhile diversion for the local youth.

Discovering a commercial interest in their material that the musicians had not anticipated, the band began recording and marketing itself.

When several songs yielded head-spinning mainstream success on the British charts, a buzz began to build and spread to the United States.

In a departure from tradition, Delirious? signed a major-label distribution and sales agreement for North America only; the band's own label, Furious? Records, maintained control of the group's releases to the rest of the world.

"Kingdom of Comfort" was produced by Sam Gibson (Pearl Jam, Crowded House, Hillsong United) and is being critically acclaimed.

Established fans expecting 60 minutes of "I Could Sing of Your Love Forever" reprised will assuredly find a taste of that. They'll also find a band that is facing tough issues of social and economic injustice, atop a dazzling, assertive sound that conjures fantasies of U2, Kings of Leon and Peter Gabriel jamming in the narthex of the local church.