There are some quotes from Kierkegaard that seem a bit pithier and clearer, but it's often dangerous to take them at face value. He was someone who wrote not only as himself, but also as an army of pseudonyms who sometimes share his views, sometimes oppose them, and sometimes come at them from an odd angle. Moreover, the whole of a work often gives a rather different context from what you might assume when reading only a single quote. But here are some good ones:“The self is a relation which relates itself to its own self, or it is that in the relation that the relation relates itself to its own self; the self is not the relation but that the relation relates itself to its own self.”
Deep within every human being there still lives the anxiety over the possibility of being alone in the world, forgotten by God, overlooked among the millions and millions in this enormous household. One keeps this anxiety at a distance by looking at the many round about who are related to him as kin and friends, but the anxiety is still there, nevertheless, and one hardly dares think of how he would feel if all this were taken away.
To be a teacher does not mean simply to affirm that such a thing is so, or to deliver a lecture, etc. No, to be a teacher in the right sense is to be a learner. Instruction begins when you, the teacher, learn from the learner, put yourself in his place so that you may understand what he understands and the way he understands it.