During this period we need to think about the Incarnation and then reflect on what we have done to become full participants in this event. Christ came to give us a rebirth. First we need to give thanks and then look at ourselves and ask, how have we done at living up to His image in which we were created? How well have we followed Him? We need to ask ourselves if we are still caught up and blinded by the needs and desires of our bodies and our self-interests. Ask, How can we lift ourselves to a higher spiritual plane to find that union with God we all deep down desire recognizing that all our other desires are but a false substitute for this greater desire?
Here is some words of wisdom for Saint Leo the Great
Let us then, dearly beloved, give thanks to God the Father, through His Son, in the Holy Spirit, Who "for His great mercy, wherewith He has loved us," had pity on us: and "when we were dead in sins, has quickened us together in Christ," that we might be in Him anew creation and a new production. Let us put off then the old man with his deeds: and having obtained a share in the birth of Christ let us renounce the works of the flesh. Christian, acknowledge your dignity, and becoming a partner in the Divine nature, refuse to return to the old baseness by degenerate conduct. Remember the Head and the Body of which you are a member. Remember that you were rescued from the power of darkness and brought out into God's light and kingdom. By the mystery of Baptism you were made the temple of the Holy Ghost: and do not subject yourself once more to the devil; because your purchase money is the blood of Christ, because He shall judge you in truth Who ransomed you in mercy, who with the Father and the Holy Spirit reigns for ever and ever.
Remember, Jesus came as fully God and fully human to save us. This requires our participation. Examine how you participate in this season preceding the feast of the Nativity.