Michael Downey, who teaches Theology and Spirituality at St. John's Seminary, Camarillo, wrote, a few years ago, Altogether Gift: A Trinitarian Spirituality.

This lovely and deeply pondered book (more suited to lectio than to quick perusal) was originally conceived as a joint undertaking with the late Catherine LaCugna of Notre Dame. LaCugna's book God for Us (which I reviewed for Commonweal back in 1993) was a milestone in the reconsideration and renewal of Trinitarian theology.

Catherine's illness ultimately prevented their collaboration, but in the "Introduction" to his book, Michael pays grateful and gracious tribute to her. He sums up LaCugna's key Trinitarian insights in three (of course!) points:

1. "Whatever is said of the Mystery of God must begin by attending to the Incarnate Word, Jesus Christ, and to the presence and action of the Spirit of God in human life, history, the church, and the world."

2. "The Mystery of God is profoundly relational , and this relational Mystery is expressed in the language of Father, Son, Spirit."

3. "The doctrine of the Trinity is an eminently practical teaching, expressing not only who and how we understand God to be, but what we think human persons are called to be and become: created to glorify God by living in communion with God and one another through Christ in the Spirit."

As the church prepares to celebrate Trinity Sunday, we might all make our own the prayer with which St. Augustine concludes his great and seminal De Trinitate:

So when we do attain to You, there will be an end of these many things which we say and do not attain; and You will remain One, yet all in all. And we shall say one thing, praising you altogether, even ourselves being also made one in You: o Lord, the One God, God the Trinity.