Dominum et Vivificantem §9

⁹ Thus in the farewell discourse at the Last Supper, we can say that the highest point of the revelation of the Trinity is reached At the same time, we are on the threshold of definitive events and final words which in the end will be translated into the great missionary mandate addressed to the Apostles and through them to the Church: "Go therefore and make disciples of all nations," a mandate which contains, in a certain sense, the Trinitarian formula of baptism: "baptizing them in the name of the Father and of the Son and of the Holy Spirit." The formula reflects the intimate mystery of God, of the divine life, which is the Father, the Son and the Holy Spirit, the divine unity of the Trinity. The farewell discourse can be read as a special preparation for this Trinitarian formula, in which is expressed the life-giving power of the Sacrament which brings about sharing in the life of the Triune God, for it gives sanctifying grace as a supernatural gift to man. Through grace, man is called and made "capable" of sharing in the inscrutable life of God.