as children of obedience, not conforming yourselves according to your former lusts as in your ignorance,
Not fashioning yourselves according to your former lusts ... A noble principle is in view here.  Through the practice of wickedness, people fashion themselves in the likeness of the sins they commit; and thus they become "sons of disobedience"  (Ephesians 2:2; 5:6;  Colossians 3:6), the very opposite of what Peter required for Christians here.