Enforced obedience is when we are told what to do. It is a stage where discipline must be used wisely. Willful obedience is a stage where, hopefully, less discipline will be required, as the child has learned the need for obedience. They willfully obey parents out of respect for parents. At this stage of life they may or may not understand what they are told, but they willfully obey.
Mutual obedience comes by successfully navigating through the first two stages of obedience.
Mutual obedience is when the child and the parent understand what is best in a given situation and they mutually submit to what is required of each. Most adults that do well with authority have had good experiences with enforced obedience and willful obedience. When parents abuse their authority, children will tend to distrust all authority. When parents fail to enforce obedience the child will grow up without an understanding of the importance of authority. As parents, we represent the authority of God.