A devout Methodist, Cruikshank entered Union Theological Seminary in 1926 and obtained a Master of Divinity degree in 1929. During his time at Union Theological Seminary, Cruikshank became acquainted with the liberal theologian Reinhold Niebuhr. Niebuhr's teachings about the social gospel as well as his deep involvement in the labor union movement (he was an outspoken critic of Henry Ford and allowed union organizers to speak from his pulpit on union issues) were highly influential in forming Cruikshank's personal beliefs and life.