Answer:
emphasize that the Great Spirit was an important influence in his ancestors' lives
Explanation:
The structure of the text develops the author's ideas by using the continued use of the word "Great Spirit" to show the great importance and influence of the Great Spirits in the life of his ancestors.
From the text, the author's ancestors had a firm belief in the Great Spirits as they were believed to be responsible for a lot of things and could bring good luck to a man and his family.