THE AMBASSADOR by Morris L West. 275 pages. Morrow. $4.95.
Morris West's best novels merit serious attention because they grapple earnestly with the private truths of religious crisis. The Devil's Advocate approached greatness. It used a fascinating but hypothetical public issuethe ecclesiastical investigation into the life of a possible saintas backdrop to the private spiritual agony of a middle-aged monsignor dying of cancer. Then West began to tinker dangerously with the balance between private and public; his novels increasingly seemed to offer the inside dope about decisions of state, competing for the attention...