Often when we think the second coming of Christ, we think of judgment. Today's first reading, however, uses a different word. The word is fulfillment. The second coming of Christ which we celebrate in the first half of Advent is the celebration of the fulfillment of the promise.
The gospel gives us the keyword if we want to participate in that fulfillment. The Greek command prosechete, literally to hold your mind.
We think of being a saint as an almost impossible task. We forget that in order to sin it requires an act of the will; we must choose. In the same way, we are equally free to choose not to sin, to be holy, to do the right thing.
This advent is a time for us to take hold of the lives that God has given us, and live each day deliberately. We may find that sainthood is easier than we think.