"Say Amen, Somebody," the gospel jewel that opens today at the West End Circle, is the brightest, funniest, most joyful--and certainly the most inspirational--film you're likely to come across in a long time. It is so chock full of wonderful people, heartfelt songs and stories that if you can resist it, it's time to get your pulse checked.

See "Amen." Everybody.

George T. Nierenberg's 100-minute film may be a documentary, but it plays like a historical epic. It has devastatingly heroic personalities, dramatic conflicts, comic relief, poignance and an exhilarating sound track. It is beautifully filmed and recorded. It celebrates bedrock faith and magnificent art even as it introduces some of the most fascinating people you could ever hope to meet.

The centerpiece of the film is the 1981 tribute to "Mother" Willie Mae Ford Smith at St. Louis' Antioch Baptist Church. Smith, 78, and the Rev. Thomas A. Dorsey, 84, are pioneer figures in gospel music, and the film traces the genre over a 60-year period.

The most eloquent, telling moments in "Say Amen" are the songs themselves, 25 emotion-drenched musical moments that course through the film like life-blood. They envelop singer and audience--in gospel, there is no distance. During the tribute--which features brilliant performances by Delois Barrett and the Barrett Sisters, the delightful O'Neal Twins, and the ecstatic Zella Jackson Pierce--Smith beams with the realization that she doesn't have to die and go to Heaven to hear the voices of angels.

Though Antioch Baptist Church is home base, "Say Amen" moves like an itinerant preacher, stopping at a storefront church, a gospel convention, workshops with Dorsey and Smith; it also goes into the homes of the performers, capturing the life behind the songs.

Some scenes are astounding: a somber, proud Dorsey slowly recounting the sudden deaths of his wife and daughter in 1933, an event that inspired him to write "Take My Hand, Precious Lord." He speaks as if the tragedy occurred yesterday, and then slides softly into lyric, each word dropping from his mouth like a tear.

There's also a wonderful scene in which Dorsey and Sallie Martin, another pioneer spirit, talk about Dorsey's initial career as a blues man. Martin, with a wonderfully sour but loving expression, is not amused when a smiling Dorsey, listening to an old 78 titled "How Can You Have the Blues," says warmly, "That's kind of smooth, man! Want to hear some blues from me? 'The blues ain't nothing but a woman feeling bad . . .' Now what's wrong with that? Nothing! If you got a good woman and she don't feel good, get her to feeling good!" His feistiness surrenders a moment later: "Say amen, somebody."

From there, Martin and Dorsey listen to themselves on another scratchy 78, "If You See My Savior," one of the earliest recorded examples of gospel. As they listen, Dorsey starts to sing softly. A moment later, Martin starts tapping her hands, then her feet and soon she, too, is singing along, transforming a genteel gospel duet into a quartet that transcends time. It's a beautiful moment.

Although Dorsey is a strong presence in the film, it's Smith whose impression goes deepest. She is very much the anointed singer who, as one daughter says, "wasn't singing for show, she was singing out of believing." Nierenberg seems to find her always surrounded by a family devoted and thankful for her gifts. Smith tells wonderful stories, chides a grandson who's something of a chauvinist, counsels a young singer on her commitment to gospel and the toll it can take on her family.

There's a poignant scene of Smith's son and daughter visiting the now-gutted train station where they frequently awaited her returns from long missions on the road; Nierenberg uses old photographs here and elsewhere to spin a web of place and time when commitments to a higher ground were set and solidified. Dorsey and Smith move slowly through "Say Amen." They also move with consummate grace--Dorsey's finger conducting an invisible chorus, Smith's eyes often looking homeward, heavenward.

"Say Amen" was funded by the National Endowments for the Arts and Humanities and the Missouri Arts Council. Never have tax dollars been better spent. Nierenberg, a 30-year-old documentarian who made "No Maps on My Taps," a wonderful film about jazz tap-dancers, spent a year researching "Say Amen," 15 days shooting and another year editing. His care and commitment show in his ability to capture the fundamental honesty of his characters and the closeness of their relationships. And cameramen Ed Lachman and Don Lenzer are so intimate with their subjects that you feel as if you are sitting right in the front pew.

"Say Amen" has enough warmth in it to melt an iceberg, and ultimately it's a splendid celebration of selflessness and spirit.

"Say Amen, Somebody" is a secret to be let in on, and the hearing and the seeing of it is believing. You don't even have to believe in God. But you will end up believing in the human spirit. SAY AMEN, SOMEBODY

Produced and directed by George Nierenberg; directors of photography, Ed Lachman and Don Lenzer; edited by Paul Barnes; sound by Danny Michael, John Hampton and Neelon Crawford; produced by Karen Nierenberg; presented by United Artists. Running time 100 minutes; Rated G. THE CAST Willie May Ford Smith Thomas A. Dorsey Sallie Martin Delois Barrett Campbell