''I do not know if Christians are still a majority in this country,'' exclaimed the little man with black Napoleon curls and fidgety hands, ''but I know that this country was built around cathedrals and church spires. And things are tolerated in this country that would not be tolerated in General Jaruzelski's Poland!''

If a fire had not gutted a Left Bank movie theater showing ''The Last Temptation of Christ'' last month, Bernard Antony would probably have remained in the obscurity that is the lot of a representative of the far-right National Front to the European Parliament in Strasbourg. And except perhaps for the police, not many outsiders had heard of his General Alliance Against Racism and for the Respect of French and Christian Identity.

But after the arson attack Oct 22 on the St.-Michel cinema across the Seine from Notre-Dame Cathedral, the police recalled that Mr. Antony vowed in August that he and other militant Roman Catholics would use more than words to halt Martin Scorsese's film and that the pugnacious politician had boasted that it would be an honor to go to jail to prevent such impiety and ''anti-Christian racism'' from being purveyed in France.

With impressive rapidity, investigators have unraveled what they believe to be an underground network of Catholic fundamentalists linked to Mr. Antony who fanned out across France, making menacing telephone calls to theaters showing the Scorsese film, daubing them with the word ''blasphemy,'' setting off tear-gas canisters and stink bombs and assaulting filmgoers. Nine people belived to be members of the band have been detained and other arrests are expected. 'Desperate Gesture'