From Longman Dictionary of Contemporary Englishbeyond beliefbeyond beliefBELIEVEused to emphasize that something is so extreme that it is difficult to believe What she did was stupid beyond belief. → belief
Examples from the Corpus
beyond belief• What Clemens did next was almost beyond belief.• They have been slashed and burned and damaged beyond belief.• The media are dull beyond belief because of the heavy censorship.• I think this is idolatry beyond belief.• These proposals are ridiculous beyond belief.• She was tired, tired beyond belief.• And the saluting was beyond belief.• Did I just frighten you beyond belief? 