Question 81: Why is the doctrine of the Trinity important?

Answer:

The doctrine of the Trinity is important because it reveals who God truly is and forms the foundation of the Christian faith. Only the Triune God—Father, Son, and Holy Spirit—can create, redeem, and sanctify. The Gospel itself is Trinitarian: we are chosen by the Father, saved by the Son, and sealed by the Holy Spirit. To know and worship God rightly, we must know Him as He truly is: one God in three Persons. (John 17:3, Ephesians 1:3–14, Titus 3:4–6, Matthew 3:16–17, Romans 8:9–11)

Full Scripture References

“Now this is eternal life: that they may know You, the only true God, and Jesus Christ, whom You have sent.” — John 17:3 (BSB)

“Blessed be the God and Father of our Lord Jesus Christ… In Him we were also chosen… In Him you also were sealed with the promised Holy Spirit.” — Ephesians 1:3, 11, 13 (BSB)

“But when the kindness and love of God our Savior appeared… He saved us… through the washing of new birth and renewal by the Holy Spirit, whom He poured out on us richly through Jesus Christ our Savior.” — Titus 3:4–6 (BSB)

“As soon as Jesus was baptized, He went up out of the water… the heavens were opened… the Spirit of God descended… and a voice from heaven said, ‘This is My beloved Son…’” — Matthew 3:16–17 (BSB)

“You, however, are controlled not by the flesh, but by the Spirit, if the Spirit of God lives in you… And if anyone does not have the Spirit of Christ, he does not belong to Christ.” — Romans 8:9 (BSB)

Expanded Explanation of Catechism Question

The doctrine of the Trinity is not a minor or abstract concept—it is at the heart of all Christian belief and practice. To deny the Trinity is to deny the very nature of the God who saves. As St. Athanasius and the early Church insisted, salvation is possible only because God is Triune: the Father sends the Son to redeem us, and the Holy Spirit applies this redemption to our lives.

Anglicans hold this doctrine as essential. The Thirty-Nine Articles of Religion begin with Article I, which affirms one God in Trinity, and Article II, which confesses the Son’s divine nature. The Athanasian Creed—a key document in Anglican tradition—boldly declares that “this is the Catholic Faith: that we worship one God in Trinity and Trinity in Unity… which except a man believe faithfully, he cannot be saved.”

Bishop J.C. Ryle wrote:

“Tell me what a man thinks about the Trinity, and I will tell you what he is. If he holds not to this doctrine, he cannot be called a true Christian.”

More recently, Rev. Dr. Ashley Null, a leading voice in Anglican theological renewal, said:

“The Trinity is not a theological extra; it is the framework of the Gospel. Without the Trinity, we do not know the God who has acted to save us.”

The Gospel itself is Trinitarian:

The Father planned our redemption from eternity (Ephesians 1:4–5).

The Son accomplished it through His death and resurrection (Galatians 4:4–5).

The Holy Spirit applies it to our hearts and assures us of adoption (Romans 8:14–17).

This truth also shapes Christian worship. When we pray to the Father, in the name of the Son, and by the power of the Holy Spirit, we are responding to the God who first revealed Himself to us. The Gloria Patri, Creeds, and doxologies in Anglican worship echo this Trinitarian pattern. Worship that does not recognize the Trinity falls short of biblical faith.

Additionally, the Trinity is not only foundational but also relational. God is love because God is Trinity—eternally existing in a communion of love. The doctrine teaches us that love is not created, but divine, flowing from the eternal relationship of Father, Son, and Spirit. To be made in God’s image is to be made for love, fellowship, and self-giving.

Early Church Fathers on Catechism Question

St. Athanasius (c. 296–373 AD): “Whosoever will be saved must above all things hold the catholic faith… That we worship one God in Trinity, and Trinity in Unity.” — Athanasian Creed

Athanasius regarded belief in the Trinity as essential to salvation and the heart of the Church’s confession. St. Augustine of Hippo (354–430 AD): “The Trinity is our highest good, our origin and end. In knowing Him, we begin to know ourselves rightly.” — On the Trinity, XV

Augustine saw the doctrine as the key to understanding both God and humanity. St. Basil the Great (c. 329–379 AD): “No one can be baptized into the Church unless he confesses Father, Son, and Holy Spirit, one God.” — On the Holy Spirit, 12

Basil tied the doctrine directly to Christian identity and the sacramental life of the Church. St. Irenaeus of Lyons (c. 130–202 AD): “The Father plans, the Son executes, and the Spirit perfects. This is the saving economy of our God.” — Against Heresies, IV.20

Irenaeus described salvation history as the coordinated work of the Triune God.