The book "Letter to the Friends and Subscribers of the Church's Pastoral Aid Society, occasioned by a letter from the Rule of Dr. Molesworth" by Caleb Whiteford is a significant work that reveals important aspects of missionary activity in the church. Describing his own experience and memories, the author addresses the readers with important questions regarding the help and support of believers. His letter reveals the depth of thought and invites discussion of important topics related to the spiritual sphere. Readers get a unique opportunity to deepen their religious views and reconsider their own attitude to the deep values of faith. This book is an intellectual challenge and a great guide for anyone seeking to deepen their spiritual life.