Trinity Sunday - Our Ecclesiastical Koinonia and the Triune Koinonia of Divine Hypostatic Homoousios

The Sunday after Pentecost Sunday, before Corpus Christi Sunday, is Trinity Sunday. There is a good reason for Trinity Sunday to be celebrated between Pentecost Sunday and Corpus Christi Sunday.

During his farewell discourse to the disciples and prayer on the night before his death (John 14-17), Jesus described all three in Trinity: the Father, the Son, and the Holy Spirit in their Trinune fellowship. Not only that, Jesus expressed his ardent desire to form the kind of fellowship he has with the Father also with us, as we are in the fellowship with one another. 

Jesus, the Son, identified his consubstantial oneness (homoousious) with the Father in John 10:30, and explained it further as the Father and the Son in each other reciprocally in John 10:38. This Father-Son unity is brought as the undercurrent for his discourse to introduce the Holy Spirit as another Parakletos (John 14:16), while he himself is Parakletos (1 John 2:1). Parakletos is often translated in English as “Advocate” or “Comforter”. But it literally means “being called to be besides or to be companion to someone”.  In John 14, Jesus the Son assured that we are always with Parakletos, either as in the human flesh of Jesus or as in the pure Holy Spirit, so that we will never be left as orphans, even though we may not be with him in person for some time being (John 14:18).  Jesus assured on the night before his death that we are always in fellowship (koinonia) with Parakletos, in the human flesh of Jesus, the Son of Mary, or in the pure spirit, the Holy Spirit. Or can be both, because as we celebrate on Corpus Christi Sunday, Parakletos in the human flesh of Jesus can be brought to us when a priest calls upon the Holy Spirit through Epiklesis during Eucharistic Prayer at Mass. In the Sacrament of the Holy Eucharist, we encounter Parakletos with his living flesh and blood, so that we may enjoy eternal life, as Jesus explained in John 6:25-65.

The context of Jesus’ farewell discourse and prayer to strengthen our fellowship (koinonia) of faith, hope, and love, by connecting it to the Triune fellowship of the Father, the Son, and the Holy Spirit, was the table fellowship of the Last Supper.  In connecting John 14-17 to Matthew 28:16-20; Mark 16:15-20; Luke 24:45-53, and Acts 1:1-10, 2:1-47, you realize that through the Holy Spirit, as another Parakletos in Jesus’ promise (John 14:16, 26), the Spirit of the Father’s promise (Luke 24:49), is being sent to us in our fellowship of faith, hope, and love, through the powerful Holy Spirit, like ruah (mighty divine wind) with tongs of fire (Acts 2:2-3), so that our fellowship (koinonia) is born into One Body of Christ through this One Spirit, the Holy Spirit, as Paul writes in 1 Corinthians 12:13, namely, we are born again of the Holy Spirit, as Jesus told Nicodemus to inherit the Kingdom of God  (John 3:3, 6-8). And, this our new birth of the Holy Spirit is the birth of the Church, Ekklesia, on Pentecost, bound for the Kingdom on earth as it is in heaven.  Therefore, on Pentecost, by being bon of the Holy Spirit, our koinonia has been born into the Ekklesia, the one, holy, catholic, apostolic Church, as in the Nicene Creed.

Because our One God is relational, God Godself is not just ousia (being) but God is divine koinonia(fellowship) among the Father, the Son, and the Holy Spirit. And, these three in this divine koinonia (fellowship), called Trinity, are in unity, characterized with homoousios (sharing the same ousia (essence, being)) but three different hypostases : the Father, the Son, and the Holy Spirit. Thus, the Trinity is the divine fellowship (koinonia) of hypostatic unity of the Father, the Son, and the Holy Spirit. And, Jesus wants to connect us, being born of the Holy Spirit on Pentecost as the Ekklesia (the Church), One Body of Christ, to be in uniformed fellowship (koinonia) with this Trinitarian divine fellowship (koinonia) of homoousios.

It does not have to be Trinity Sunday but any day whenever we celebrate Mass on any day (except for Holy Saturday until Paschal Vigil), because the presiding priest reminds us that we are, indeed, in koinonia not only with each other but with our Triune God as the Ekklesia, as Mass begins, evoking 2 Corinthians 13:13, “The grace of our Lord, Jesus Christ and the love of God and the fellowship of the. Holy Spirit be with you all”.

Both the Son and the Holy Spirit are sent by the Father as gifts to us, because God is love, and out of His love (John 3:16). And, the Son, though pre-existed the Creation (Hebrews 1:1-11; John 1:1-18; Colossians 1:16; cf. Proverbs 8:22-31), has been sent to us, by the Father’s love, in the human flesh of Jesus through Mary’s Immaculate flesh, by the power of the Holy Spirit (Matthew 1:18; Luke 1:35), so that he, as Emmanuel (God with us)(Matthew 1:23; cf. Isaiah 7:14), can dwell among us (John 1:14) in our koinonia (fellowship). Then, through this Son, Jesus, Parakletos (1 John 2:1), we have received another grace, the Holy Spirit, as another Parakletos (John 14:16) for a greater fellowship (koinonia), being born to One Body of Christ (1 Corinthians 12:13), the Ekklesia (the Church), in which Corporis et Sanguinis Christi are found in the Sacrament of the Eucharist by the power of the same One Spirit, the Holy Spirit through transubstantiation of offered bread and wine for our table fellowship (koinonia), communion, with our Lord Jesus Christ, who is in the hypostatic union with the Father and the Holy Spirit.