At the age of 14, during the Second Great Awakening, which was especially strong in Upstate New York, Briggs experienced a conversion experience and joined the Baptist faith. He spoke at revival meetings of his experience, drawing appreciative applause from the crowds, according to Hiland Hall, who came to know Briggs at that time and who became a lifelong friend and political associate. His faith informed his personal behavior: he remained committed to religious ideals, for instance objecting to Congressional sessions that stretched into Sunday and abstaining from alcohol consumption.