According to the Christian doctrine of the Trinity, there are three persons in one God: Father, Son and Holy Spirit. The Scriptures are not much interested in the philosophy or metaphysics of God. They are mainly concerned with God in relationship with Israel in the Old Testament and with the church in the New Testament. They insist that the God of the Bible is with us, for us and even one of us.
The Old Testament reading for Trinity Sunday is from Deuteronomy 4. It concerns the person of the Trinity whom Christians know as God the Father. It focuses on God’s relationship with his people Israel. It recounts some of the most important events in the history of salvation: God’s creation of humankind, God’s election of Israel as the chosen people, God’s liberation of this people from slavery in Egypt and God’s gift of the Mosaic Law as a means of shaping his people and guiding their response to him. God the generous giver is with and for his people.
The passage from the end of Matthew’s Gospel has been chosen for Trinity Sunday largely because of its trinitarian baptismal formula “in the name of the Father and of the Son and of the Holy Spirit.” These are the words of the risen Christ as he commissions his 11 apostles (minus Judas) about how they can carry on the work that he had begun. The text is a summary of the entire Gospel of Matthew. In the context of the Christian trinitarian doctrine of God, Jesus is more than Abraham or David, more than a wise teacher or a powerful healer, more than the prophet of God’s kingdom. Rather, Jesus is Emmanuel (“God with us”) and is on the same level as the Father and the Spirit. He stands out as the pivotal figure in the narrative of God’s relationship with his people Israel and as the definitive proof that the God of the Bible is with us and for us until the end of time.
The short passage from Romans 8 speaks of the Father, Son and Holy Spirit and of our relationship with each of them. As part of Paul’s long meditation on life in the Spirit, it focuses on the role of the Holy Spirit in Christian life. By leading and guiding us, the Spirit makes it possible for us to be children of God and to address God as Jesus did, as “Abba, Father.” Moreover, the Spirit enables us to be joint heirs with Christ to God’s promises. Just as Christ has shared our humanity, so we can share his divinity. Again the Scriptures are concerned primarily with the Spirit in relationship to us as God’s people in Christ.
The God of the Scriptures is always in relationship with his people and is passionately concerned with creation and the successes and failures of humankind. The God of the Bible is not only with us and for us, but in the incarnation of Jesus as the Word of God has even become one of us. And God continues the work of creation, redemption and salvation through the Holy Spirit.