Prior to this point, Rimmer had shown little interest in religion. However, while returning from a prizefight he was converted to Christianity by a street preacher, and retreated to the Lake County woods with a Bible to master the tenets of his new faith. Thereafter Rimmer went to the Bible College of San Francisco (where he met his wife), and then in 1915, to southern California, where he studied briefly at Whittier College and at the Bible College of Los Angeles (now Biola University) and served as pastor of a Quaker church. In the early 1920s, Rimmer abandoned the Quakers for Presbyterianism and worked as an itinerant speaker for the YMCA. He took advantage of this contact with young men to evangelize and proselytize. He often spoke at churches, secular and religious colleges, military installations and Bible conferences.