In I Corinthians 12:4-6 Paul definitely spoke in purposeful Trinitarian terms in order to make his point about God’s desire for unity amidst a diversity of gifts in His church:
— :4 “Now there are varieties of gifts, but the same Spirit”
— :5 “And there are varieties of ministries, and the same Lord”
— :6 “There are varieties of effects, but the same God who works all things in all.”
In the three consecutive verses Paul employs three different words for deity: “Spirit”, “Lord”, “God.” These refer, of course, to the Holy Spirit, the Lord Jesus, and God the Father. It is obvious that Paul is referencing the Triune God to make his point.
And he employs the Trinity in more than name only. The diversity of the gifts (or better the “roles”) of each member of the Trinity — while still maintaining their essential unity — displays the ultimate example of what Paul is teaching here: that the diversity of gifts in the church are still to be employed in unity. God the Father, God the Son, and God the Holy Spirit each play different roles in the divine economy — and yet they are absolutely ONE, as the scripture repeatedly makes clear.
Paul doesn’t “spell it out” for us — and yet this text relates it as clear as day. The different roles, and yet essential unity, of the Persons of the Trinity serve as the perfect model for for us to live with similar diversity — and yet perfect unity — in His church.