The next encyclical of Pope Pius XII is Mystici Corporis Christi (“On the Mystical Body of Christ”) written in 1943. By “Mystical Body,” the pope is referring to the Church and this document gives a thorough teaching on what we mean when we say “the Church is the body of Christ.” So, we’ll take it a little at a time and see what it says.
To start with, Pope Pius says he is speaking specifically about the Church Militant, which refers to the Church on earth. The Church exists in three parts: Militant, Suffering, and Triumphant. The souls in purgatory are the Church Suffering, the souls in heaven are the Church Triumphant, and all living Catholics on earth are the Church Militant – called that because we are still battling sin and the devil. To this the pope adds that we should “glory in a thorn crowned Head” and that we should “rejoice if we partake of the sufferings of Christ” because we know that that leads to everlasting joy. This is in part because he is writing during World War II, so he takes time to acknowledge the great destruction and suffering taking place around the world.
Pius XII then identifies the two opposite extremes of error that he wants to protect against: Rationalism and False Mysticism. The correct way is “reason enlightened by faith” which can give us real knowledge of the mysteries of God as revealed to us in Scripture and Tradition. And Scripture clearly calls the Church the Body of Christ, who is the head. This body must therefore be unified to be a real body and it must also be visible. Like any body, the parts are connected in a structured way. This structure includes the hierarchy (deacons, priests, bishops) but is not limited to that. Indeed, the Church fathers and scripture itself speaks of the many members who make up the Church but are not ordained ministers: people who serve through various charisms and states of life. It’s worth pointing out that the pope specifically names parents and godparents as expressions of this body that is the Church and calls on them to be holy because of that.
From there, the pope explains that the Seven Sacraments are an integral part of what makes the Church the Church because they are how we add members to the Church, strengthen them, give them a mission, and bring them healing. In particular, the Sacrament of the Eucharist unites all Catholics in Christ, the head of the Body. This Sacramentality, however, means that only those who are baptized and have faith are members of the Body. Still, this does not mean only saintly and holy people are members. Even when members lose grace through sin, they are not fully cut off from the body so long as they hold to faith and hope. In other words, even the weakest members of the body are still members. Only obstinacy in sin and unbelief will cut someone off.
As this was written during the height of World War II and the Holocaust, the pope makes sure to address race. Drawing on St. Paul’s teachings and the many symbolic and prophetic acts of Christ, he points out that the Church is composed of Jew (ethnically speaking) and Gentile. Jesus brings to completion the Old Testament and tears down the dividing wall between the chosen Israelites and the rest of the world. As such, there is no room for racism within the Church and the Church stands against it in the world as well.
Then Pope Pius XII focuses on what it means for Christ to be the head of the body, the Church. In short, Christ is the head because it is his teaching that we follow, because he is the source of our grace and holiness, because he is God who created us, and because, by the Holy Spirit, he is the one we obey in the daily practice of our religion. The hierarchy of the Church is established by Jesus and entrusted with his own authority, so the governance of the Church is ultimately his and is only exercised vicariously by the priests and bishops. Because the Church is a united body and there is only one head, so there is only one Vicar directly representing that head: the Pope. This is a key reason for the existence of the papacy: to be a visible reminder of the unity of the Church organized under the one head, Jesus Christ. In each diocese, the bishop is a reflection of this fact, acting as the symbol of unity for a particular area, though ultimately united to and under the one Church. From here, Pope Pius XII is going to address what being part of the body means for us and we’ll pick up there next week. In the meantime, pray for the unity of the Church!