As stated earlier, Sunday School exists for its students. So study of the student is the all-important thing in this book. Everything is based upon the human heart, the soil in which the Sunday School teacher sows the truth. As a child grows from infancy to adulthood, there are three distinct periods of development that are passed—childhood, youth and adult—that have characteristics so definite that they may be easily marked. All are part of the sowing field of our