''RESURRECTION'' is a movie about faith, and one that must be taken on faith. It's a little bit mad. But it has the courage of its conviction, and a beauty and persuasiveness that help keep the doubts at bay. You may not be far out of the theater before the film begins to seem silly. But the measure of its sincerity is the experience of watching it, which is a very uncomplicated one. Believe, the movie says, and for a while you really do....this is a movie that really seems to have brought out the best in everyone who worked on it. Chief among them is Miss Burstyn, who gives the kind of performance that makes all the odd events in the screenplay seem perfectly plausible, perfectly sane. Her presence is radiant, and so steadying it lets the movie exert a tremendous emotional pull.