Fuzzy on God?

We were driving home from this morning's worship service, and began talking about God. I commented that my friend's message was the best biblical message about God that I had heard at the church he serves at. My wife responded that I should tell my friend what I meant by my comment that it was the best biblical message about Christ. I said, No. Not about Christ: about God. My daughter responded: Jesus. Christ. God. Three in one, right?

Her comment spawned several thoughts and recollections. One was a comment attributed to Gregory of Nyssa.

When I say God, I mean Father, Son, and Holy Spirit.

I recall first reading Gregory's statement, and thinking, "OK: what's the point?" The statement came in that Gregory was defending the Nicene Creed in responding to Arius and his colleagues . The aim was to reassert that Jesus was not a created pre-existing creature that Arius asserted, and if any of distinctiveness of the members of the Trinity could be understood, that came from the mutual relations that exist between the members. But, he implicitly wanted to simultaneously reaffirm for pastors, missionaries, and evangelists that use of the name "Lord" or "God" (I know: both are English words!) would encompass all of the persons of the Trinity.

So, when many (most?) people like my daughter speak about the "three-in-one" God, a kind of fuzziness of names and relations can be heard: frequently. It doesn't reflect well what Gregory and others have taught and handed down. And, I often wonder, how well do my family and friends know about the Trinity?

What do you think? As we consider matters of worship, prayer, ethnic identity, fellowship, gender, evangelism, racial reconciliation, and justice: in our journey of faith, how crucial/important is knowing God as three-in-one?