Isaiah  48:17.

“I, the Lord, your God, teach you what is good for you, I lead you in the way that you must go.”  

The idea of Christ as Teacher was a strong image that St Augustine used frequently. As the following quote states he clearly saw Christ as the teacher within.

“Your true teacher will always be the Teacher within. It is He who enables you to understand in the depths of your being the truth of what is said to you.”

Here we touch on Augustine's concept of Interiority. Like all the major seasons of the Church's year, Advent is a time to get in touch with our inner self and so discover the God within. During this season of Advent if we give ourselves the space and time for prayer, we like Augustine will hear the voice of Christ, the Teacher. It is only when we let God teach us that we will understand what is good for us and that we will find ourselves on the right path, as Isaiah points out in the first reading from today's Mass. So let Advent be that time when as St Augustine puts it so well we “Let Christ speak to you interiorly, in that place where no human teacher can enter.”