In the field of psychology, "locus of control" refers to the extent to which a person believes they can control the world around them. People with a strong internal locus of control tend to attribute the outcome of events to factors under their own control. People with a strong external locus of control attribute outcomes of events to external circumstances. But both have a perspective which influences and predicts their actions. The book of 1 Peter is about that big perspective. In a sense, Peter is writing to explain a "gospel locus of control."