Jesus wants us to both believe in his truths, and also be be open to new truths, ideas, data, and concepts which he, and the Father, and the world, show us. How do we keep this tension between being firm in what we know, and humbly open to new teachings?
This concept of humbly admitting one's ignorance and need for teaching is more fully talked about in this video which speaks of John 9 and the story of the man born blind.