HIS VISION OF THE MOST HOLY TRINITY.
All Christians ought to be not only devout but absolutely devoted to the most Blessed Trinity. It is the most august and fundamental of all our mysteries; it is that to which we are consecrated by our entrance into the holy Church, for we are baptized in the name of the Father, of the Son, and of the Holy Ghost.
But you, my sisters, ought in an especial manner to be devoted to this great and ineffable mystery, remembering the wonderful vision which our Blessed Father, your founder, had on the day of his episcopal consecration. In that sublime vision Almighty God showed him most clearly and intelligibly that the three adorable Persons of the most Holy Trinity were operating in his soul, producing there special graces which were to aid him in his pastoral office, at the very moment that the three Bishops who were consecrating him, blessed him, and performed all the holy ceremonies which render this action so great and so solemn. Thenceforth he always regarded himself as consecrated to the ever-Blessed Trinity and as a vessel of honour and sanctification.
Then, too, in the year 1610, he both founded and opened your Institute on the day dedicated by the Church to the memory and adoration of that incomprehensible mystery. Trinity Sunday that year happening to fall on the Feast of St. Claude, he gave you that saint as your special intercessor with the most Holy Trinity.
Again, you Congregation began with three members only, and this of set purpose, in order to honour the Blessed Trinity as well as to accomplish what is written in the Gospel, that when two or three are gathered together in the name, that is to say, for the glory of God, He will be in the midst of them, and will animate and govern them by His spirit; the spirit of love, unity, and concord, which makes us keep the unity of the spirit in the bond of peace, and renders us one through love, as the Father, the Son, and the Holy Ghost are one only, in nature, essence, and substance. It is this peace of God, passing all understanding, which has up to the present time kept all the convents of your Order in unity. Woe to him who shall break down this defence and rampart! May the ever-Blessed Trinity avert this misery, and both regard and preserve you always, as adopted daughters of the Father, adopted sisters of the Son, and spouses of the Holy Ghost! Amen.
Source: The Spirit of St Francis de Sales