Man’s greatest desire is nothing less than God Himself. It’s not just a desire to be with God though; it is a desire to be God. This is what the most Holy Trinity made us for: to partake of His very nature and, hence, to become divine. The only way that this can happen is through union with Jesus Christ the Lord God.
God came into the world through the Incarnation, His conception in the womb of the Blessed Virgin Mary. We too are called to conceive Christ within us. He desires to be conceived spiritually in our hearts.
In imitation of Mary, having conceived Him we are to bring Him to others proclaiming the Good News of our salvation. Others are to encounter Him and be aware of His presence through their encounter with those who have conceived Him in their hearts.
And like, His mother, we are to give birth to Him. It is not enough simply to bear Him within ourselves; He must come without and be present in the world. How does one spiritually give birth to the One conceived in our hearts? As one grows and develops in the womb so too does He grow in our hearts, changing us until our will, our intellect, our passions, our body and soul are His. The whole given over to Him so that with St. Paul we can say, “I have been crucified with Christ, and I live now not with my own life but with the life of Christ who lives in me.” Giving birth hurts.
Having been born He is revealed as the Light of the world to all who have eyes to see and ears to hear. We become a light of the Light: to see one is to see the other: “I am in my Father and you in me and I in you.”
But all of this requires a response. He first comes down to us, but we must embrace Him. To do that we must go where He is, His Father’s house, the Church. Only in the communion of the Church are we able to receive and conceive the Lord God in our hearts. Only in the communion of the Church do we find and rest in our heart’s desire.