Since you seem to be asking about teaching English, I would argue that using actual literature is very important. This includes novels and nonfiction, short stories and poetry. English teachers also need to directly teach writing, and not simply tell students to write.
I think that part of what drives this question has to come down to pedagogy and what particular pedagogical approaches one takes in the classroom setting. I am not sure there is one "best" method, as much of it is going to depend on a variety of circumstances. The needs of the students probably become the largest determinant in how one embraces a particular approach to instruction. One's methodology can be ingrained, but if one is a reflective educator, there has to be some level of rumination about which approach would best work with a particular group of students. Some students' needs are met through direction instruction, while another group could best be reached through an establishment of a collaborative atmosphere to teaching and learning. I think that teachers who possess a great many methodologies with which they are comfortable and can adapt what they do to the particular needs of their students. I think that any discussion of methods has to be understood in this mindset.