Trinity Sunday, very appropriately takes place on the Octave day of Pentecost, since the Holy Spirit descended upon the Church to stay on Pentecost. Moses reminds the Israelites in Deuteronomy that God, the Father, chose them to be His special people. He desired union with them through their devotion to Him and His statutes. And Christ, the Second Person of the Trinity, before His Ascension, tells His apostles that all nations are to be made disciples and baptized in the name of the Trinity. And Saint Paul writes to the Romans that the baptized have received the spirit of sonship. Through our baptism we enter into the very life of the Trinity; and we are called to suffer so that we can be glorified. We are a part of the Body of Christ as God’s children.
In the liturgical year, after Pentecost, we are not simply in “Ordinary time,” but we are to remember our identity as children of God. We have waited for the coming of our Messiah, celebrated the birth of Jesus, persevered through our Lenten penances, celebrated the Resurrection, received the Holy Spirit on Pentecost, and now we must live the Christian life everyday. We must live our participation in the Divine life. We must persevere and do our part to make disciples of all nations.