When trinitarian theology begins with questions of the Spirit, the classical conciliar trinitarian tradition can be enriched with a more dynamic and perichoretic account of triune relations that does not bring into question classical commitments to God’s aseity, simplicity, or unity. Beginning with the biblical account of the Spirit, we are drawn to Christ, and through Christ to the Father, only then can we develop a doctrine of the immanent Trinity and allow a theo-logic to enable a constructive theology applicable to all times, peoples, and places. What Third Article Theology (TAT) highlights in this very standard theological method is the mission and procession of the Spirit as a starting point in understanding God’s economic work and how this informs our doctrine of the immanent Trinity. TAT allows the relational character of God to be clearly perceived and enriches the received tradition by removing obstacles to ecumenism and retrieving a dynamic trinitarianism eclipsed at times throughout church history. Each of these points is established by the Holy Spirit and his spiration and mission. The specific claim of TAT is that by focusing on the person and work of the Spirit we can (more?) clearly establish the fundamental tenets of orthodox trinitarianism whilst also gaining new insights into the Being and Act of the triune Lord. By looking at the Father and the Son through the Spirit, the doctrine of the Trinity takes on a distinctly relational ontology whereby there is an “eternal simultaneous non-sequential symmetrical perichoretic fully-in-act relations of the fully-in-act Father, the fully-in-act Son, and the fully-in-act Holy Spirit” (Weinandy). It is just this doctrine of the triunity of God that is classically orthodox and yet, subtly under represented in much contemporary theology. TAT has an ecumenical interest and by looking at the Trinity through the Spirit we may find more common ground between the various Christian traditions.