IndependentOnSundayLutherReview

Fighting for a better world sounds like a good idea and, in 16th- century Germany, Martin Luther leads the way. In the National's bold revival of Luther - John Osborne's rarely aired history play from 1961 - Rufus Sewell is zealous as the titular friar who sparks off the Protestant Reformation. He sprays saliva when preaching from his pulpit, scorning Rome as a giant latrine and damning the Pope's greedy trade in indulgences. Nonetheless, his conscience seems troubled when he's accosted by a knight (a battle- wearied Andrew Woodall) who blames him for stirring up terrible wars including the peasants' uprising.

This portrait of Luther is ambiguous, reflecting Osborne's conflicting anti -establishment and conservative impulses. The playwright was a Protestant and Luther is the scourge of high-handed Catholic corruption as embodied by Richard Griffiths' Tetzel - a porcine Dominican. Then again, our Luther is Wittenberg's dangerous equivalent of Jimmy Porter (from Osborne's 1956 bedsit scorcher, Look Back In Anger). Holed up in a cloister against his scoffing, mercenary father's wishes, Luther has grown neurotically obsessed with his own and others' vices. In Freudian terms, God and the Pope are substitute fathers whose approval he craves, yet against whom he rages. You may even see him as demonically possessed. Note the frequent allusions to troubled bowels. Whatever his character's moral status, Sewell redeems his stage reputation here after his dire West End Macbeth. Granted, when he alludes to his revolutionary use of rough German in a polished accent, you wonder if his Luther shouldn't be more earthy. Nevertheless, he grapples boldly with feverish speeches, articulates theological arguments with intelligence and mellows as the years pass. In winning contrast, Malcolm Sinclair's Cardinal Cajetan - pressing Luther to recant - is splendidly cynical and suave, with vestiges of humane wisdom.

The bad news is Osborne is a bore in the first half. One historically looks back in a torpor as Luther's Augustinian order subject us to prolix investment ceremonies and Bible readings. Crude comic relief is no compensation. One barely senses Luther's impact on the world either, as he debates with mentors in secluded retreats. National Theatre punters, directly addressed as the Renaissance masses, didn't seem thoroughly roused. Peter Gill's production is admirable - staged in a vast arena dominated by a towering cathedral portal - but it would be a miracle if this play packed out the Olivier. Still, if you're Lutheran, your mission isn't about sales.