teaching and learning

The more I work with education students and inservice teachers the more I see a hear numerous definitions of  teaching and learning.  Even with this multiplicity of definitions what I repetitively see is the difficulty teachers have of giving up their "power" in the classroom to move towards more child initiated practices.  This loss of control seems to be a primary reason for teachers struggling to implement more creativity into the classroom and projects.  So, before I write more on this topic I am very curious to know what others think?  How do you define the role of the teacher, what does it mean to learn, and why is it so important for teachers to have this sense of power and control?