Who is Gabriel Grimes from Going to Meet the Man and what is their importance?

Gabriel is the patriarch of the Grimes family. He was once a pastor in his own church and is now a deacon in the local church, thus, he believes himself to be saved. He often forces his religious beliefs on his children. Unfortunately, he is also an abusive man who often beats his children, particularly John. Gabriel is angry because John isn't his child, and he takes his anger out on John.