Can someone explain ''signs of difference, of Godlessness'' in chapter 5?

Grandfather often, other than to note he used the word “sinner” in almost every sentence. It is clear there is no bond between Kambili and her Grandfather. He is a looming figure synonymous with his faith, devoid of personality. When Kambili and Jaja visit Papa-Nnukwu for their allotted fifteen minutes, Kambili searches for godlessness in his face. She doesn’t find anything. Moreover, she wishes to stay and take care of her grandfather. There is a connection to her ancestors that her father is not able to blot out.