How many letters does the top answer for “author of the genius of christianity” have?

The most common answer is chateaubriand (13 letters).

Crossword clue: author of the genius of christianity

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

chateaubriand 13 letters wd-fact-v3

a very thick center cut of beef tenderloin

author of mere christianity 50% similar → lewis

author of the essence of christianity 50% similar → feuerbach

wrote the genius of christianity 50% similar → chateaubriand