Although generally a quiet man, religious skepticism was known to raise his ire, and he was often blunt in defending his beloved faith and church. An oft-told anecdote has Crerar "…exclaim in a tone of impatient disgust, at hearing some one ask if he really believed that Jonah was swallowed by a whale, 'Oh! bosh! What has that got to do with religion?'". As the Church moved and expanded, Crerar supported it through labour and capital, ultimately leaving it in his will $100,000, "…so long as said church preserves and maintains the principles of the Presbyterian faith." He also left $25,000 to the Second Presbyterian Church of New York, and $50,000 to the Presbyterian League of Chicago.