Unborn Jesus and The Church
“It is clear therefore, in the light of the redemption, that the Church did not come into being only when Peter and John and Paul became believers. It became objectively existent when the divine Word united His nature with human nature in the unity of His person. The Incarnation is for Christians the foundation and planting of that new communion which we call the Church. The Body of Christ and the Kingdom of God came into being as objective reality at the moment when the Word was made flesh.”
The Spirit of Catholicism
But the knowledge and love of our Divine Redeemer, of which we were the object from the first moment of His Incarnation, exceed all that the human intellect can hope to grasp. For hardly was He conceived in the womb of the Mother of God, when He began to enjoy the beatific vision, and in that vision all the members of His Mystical Body were continually and unceasingly present to Him, and He embraced them with His redeeming love.
Pope Pius XII
Mystici Corporis, The Mystical Body Of Christ And Our Union In It With Christ #75