The principal challange of "The Challenged of the Cross," which opened a week-long run at the "Warner Theatre last night, is for the audience to stay awake.

"Cross" is an inert, inept religious pageant. It began an hour late last night and slogged through two hours of static staging, scratchy sound, campy visual effects and sanctimonious haranguing.

Practically immobilized at the center of the stage was a Bible-quoting figure in a white robe that looked strangely like a Ku Klux Klan outfit. Michael Howell, who played this role, has such an overbearingly stained-glass voice that he turned the character into a prig and made the sinners on stage lively and fascinating.

The show's musical base is gospel. Never has gospel seemed less rousing. Vinnette Carroll, who raised the roof of Fora's Theatre with a gospel treatment of similar subject matter, in "Your Arm's Too Short to Box With God," should be summoned for emergency relief.

Back Alley Productions - which has staged some provocative fare at its small uptown playhouse - is inexplicably co-producing "The Challenge of the Cross" with Gospel World Productions. If this is what Back Alley does with a big theater, it should head back to Kennedy Street.