The motto of the Holy Father's coat of arms Leo XIVIn Illo Uno Unum" (In Him who is the One we are One) may seem to us like a Latin riddle. The motto - as is well known - is taken from St. Augustine's homily on Psalm 127.
This type of expression is frequent in St. Augustine's writings. For a bishop, it is important to choose his motto Episcopal motto and, later, in the case of Leo XIV, to ratify it as his papal motto. He himself has confessed that this motto reflects his way of thinking and living as a Christian and as a bishop.
In an interview with the Vatican media in July 2023, two months before he was created a cardinal, Robert Francis Prevost explained the importance of this motto in his life and ministry. As an Augustinian, he said, unity and communion are central tenets of his vocation. To be in no doubt about this fundamental importance of communion and unity in the Church one need only read and meditate on chapter 17 of the Gospel of St. John.
St. Augustine and Psalm 127
But let us go to the source from which the motto is taken. St. Augustine wrote an extensive exposition on Psalm 127. The saintly bishop of Hippo emphasizes in his exposition the importance of counting on God in the protection of the city and in the construction of the family home. Without God's help, human efforts are in vain. It is a hymn to the family of those who fear the Lord. Everything depends on God's help, even the future of the children. The prosperity of the children is a divine blessing.
But St. Augustine wonders if this blessing of Yahweh is not also fulfilled in those who do not fear the Lord. It is evident that there are families with children in which the Lord is not feared. For this reason, St. Augustine proposes to his faithful a Christian interpretation of the psalm, looking to Christ as the fullness of Revelation. "Let us couple spiritual things to spiritual things," is how the homily begins. To this end, he turns to a theological reality dear to him and constantly preached by him: the unity of the faithful with Christ.
We form one Body with Him, and what is His Body? His Church, as the apostle says, "We are members of his Body" and "ye are the body of Christ and his members". Now there is only one man who is thus blessed with the blessing to which the psalm refers: it is Christ.
Only he fears the Lord who is among the members of this One Man. They are many men and one Man alone; many Christians and one Christ: "In Illo Uno Unum". He is the only recipient of the divine blessing.
