People might object that thinking about God, especially in terms of the Trinity, takes away from the importance of the gospel message and Christian living – but in Romans 8:12-17 we see practical instruction in Christian life with an account of the three Persons of the One God.
Paul continues the argument that it is no use doing as you want and feeding your own ambitions and appetites (even if that is to be religious or “good”). That way lies disaster. The alternative is a life powered and directed by the Holy Spirit, freely given to believers. In this way they become children of God – we might say “God the Father”, from whom every family is named (Ephesians 3:15). The ancient world knew about adoption, and took it very seriously.
In this way, as children of our heavenly Father, we share the benefits of Christ, the natural Son, and are given a place in that family.. Paul has been describing Christian life, lived not by moral effort, but by grace. It makes constant use of forgiveness to bring and keep us in relationship with the three: Father, Spirit and Son. The Trinitarian language is almost incidental and quite natural. At the same time, the effect is to create a life, supported in these different ways, but never torn between the different persons offering support.
Thinking of God can be confusing – our minds are too small. What we are given is a glimpse of wonder, to encourage praise, worship and thanksgiving. At the same time, we are told how this God brings us to share in relationship, both with God and with others. Relationships which we often get wrong, but which imitate the wonder of divine love.