Having laid out the need for a single visible head in the Church (the Pope), Pope Pius XII turns to the three virtues that manifest the unity of the Church: Faith, Hope, and Love. These connect Catholics to each other and to God. Citing several passages of the New Testament, the Pope focuses first on faith.
We share one faith in the sense of having the same beliefs. We have the same faith in the sense that the one Holy Spirit grants us the gift of faith. We have the same faith in that believing requires us to submit to one and the same authority of Christ entrusted to His Church. Finally, genuine faith means the Christ himself dwells in our hearts and draws us to perfection in faith – the one and only Jesus Christ in each of us makes the unity between believers real.
This in turn leads to a unity of hope. By faith, we are being drawn towards eternal life. We share the same Christian hope of desiring the Kingdom of Heaven. So, we are united in the sense of sharing the same goal.
Of course, love (also called “Charity”) is central to the unity of the Church. St. John writes “God is love and he that abides in love abides in God and God in him” (1 John 4:16). So, we are united by the fact that the one and only God dwells in each of us by love and that each of us abide in the same God by love. One of the ways this is manifest is by the gifts of the Holy Spirit, the charisms, that God gives to believers for the sake of serving one another.
From here, the Pope points out the most significant sign of unity: the Eucharist. Through the Holy Sacrifice of the Mass, Catholics of every time and place are united in and through Jesus Christ. The priest not only represents Christ in the sacrament, he represents the “whole Mystical Body and… each on of the faithful.” Mimicking an ancient reflection, the Pope notes that bread itself is made out of many grains formed into a single loaf. This comparison cannot be taken too far, however, and become an excuse for blurring the distinction between Christ and the Church. While we often speak of the mystical body as a union, we still hold that there is a difference between the Mystical Body of Christ, the Physical Body of Christ, and the Social Body of Christ. The physical body is Jesus’ body that walked, talked, was killed, and rose from the dead. The social body is all the faithful who form a kind of society or organization. The mystical body is the overarching unity between these two, but without losing the distinction.
Now, a key part of this unity is that it is Jesus Christ himself who is active in each of us: “without me you can do nothing” (Jn 15:5). But this does not justify what Pope Pius XII calls Quietism. This reduces all spiritual growth to a passive waiting for the Holy Spirit to do everything. While we cannot do anything without God, it does not mean we do nothing and God does everything. Rather, it is meant to remind us that we cooperate with God in growing in virtue and holiness. This is why constant prayer, regular confession, and frequent use of the Sacraments are so important. They exist because of our union with Christ and they strengthen that union with Christ. This union also extends into personal and private prayer. Precisely because each believer belongs to the Mystical body of Christ, their own private efforts contribute to the good of the whole. This is a key part of the communion of saints. Yes, the public and official prayer of the Church (blessings, Mass, etc.) has a greater dignity, but this does not exclude or diminish the real power and dignity of personal prayer.
The value of personal prayer is like the value of personal acts of love. Because we participate in the greater whole and because our lives are supposed to manifest that greater whole, we should strive to be holy. This holiness is not just an invisible quality, but shows forth also in what the pope calls “effective love.” This is shown in obedience to the moral precepts of the Church, in acts of voluntary mortification (self-denial and penance), and in positive acts of charity for our neighbor. Pius XII says that those who take seriously their place within the Church “will take to their hearts those members who are the object of our Savior’s special love: the weak… wounded… sick… children whose innocence is exposed to danger… and finally the poor.” So many struggle to see the unity of Christ and the Catholic Church. Our job is to make that easier to see through such love. Pray, therefore, for the grace to see it, live it, and reveal it to others.