The Holy Trinity is impossible to understand, but we can probably understand what it means to be a Trinitarian Church: a Church that is called and empowered by the Holy Spirit to go out and proclaim the good news of Jesus Christ in word and in deed to the world that God created and loves.
This makes the affirmation celebrated on Trinity Sunday not a mere abstraction irrelevant to the vital events of the day, but a conviction about who is at work in those events, and a mission statement about our task in relationship to them.
Our awesome pastor, as I heard it.
Matters of Interpretation 