The teacher should:
(1) personify culture and reality for the student
(2) be a specialist in human personality
(3) be capable of uniting experience with enthusiasm
(4) merit students' friendship
(5) awaken students' desire to learn
(6) realize that teaching's moral significance lies in its goal of perfecting human beings
(7) aid in the cultural rebirth of each generation
That is a long list of qualities for a teacher to have. Not that I think its wrong. In fact, I think a teacher should strive to be all of those and keep them in mind at all times.
Idealism gives us this idea of a teacher who not only knows the subject matter and delivers them well, but does so in a way that gets the student to be interested and to discover for themselves the answers to the questions. It is an education defined by the Absolute and we, as humans, are limited and can only really get a glimpse of that Absolute. But, the more in line we are to that absolute, the closer we get to the ideal.
This idea of a teacher also presupposes a lot of things like the fact that the teacher should be a model and a mature representation of culture. It invites me to think that to be a teacher, you have to constantly learn and grow too (to be always attuned to culture and reality). A teacher cannot be stagnant and assume that what was right in the past (and in his experience) will always be right. A teacher cannot be an unchanging expert and shell out the answers as if they were the only truths.
Practically speaking, I don't think the qualities of the teacher at the start of this post can ever be fully achieved by any one teacher for a long time If only that in order to fulfill those qualities, you also have to be constantly faced with uncertainty and new things that will contradict your previous notions of what is right. But that is precisely what it may mean to be a good teacher. It is to learn to be a good teacher and keep on learning as you go through being a teacher.
To be a good teacher is to guide your students as best you can to that ideal but at the same time, also being open to learn and be a better teacher along the way.