06/01/2026
Whenever Trinity Sunday comes around, many Christians become a little nervous. We know we are supposed to talk about the Trinity, but we are not always sure where to begin. Do we start with theology? Do we start with philosophy? Is it math? Do we break open an egg? Do we start by trying to explain how God can be one and three?
The Church has spent centuries trying to find language to describe the mystery of the Trinity, but I am convinced that the doctrine makes the most sense when we begin not with abstract ideas about God but with God’s saving work among us. The doctrine of the Trinity did not arise because the early Christians were trying to solve some mystery. It arose because people encountered a God who was active among them for the sake of their salvation.
They experienced the Father who created them and loved them. They encountered the Son who entered history, took on flesh, died, and rose again for their salvation. They received the Holy Spirit who transformed their hearts, gathered them into the Church, and empowered them for holy living. The question was never, “How can God be three and one?” The question was, “Who is this God who has done such marvelous things for us?”
In that sense, the Trinity is best understood by people who know they need salvation. It is best understood by people who have experienced God’s mercy, forgiveness, healing, and grace. The Trinity is not first a doctrine for philosophers. It is a confession made by redeemed people.
One theologian who understood this well was Karl Rahner. Rahner famously wrote, “The economic Trinity is the immanent Trinity, and the immanent Trinity is the economic Trinity.” At first glance, that sounds intimidating, but the idea is actually quite simple.
The economic Trinity refers to God as he reveals Himself in history. It is the history of Gods redeeming grace. It is the Father creating, the Son becoming incarnate, the Son dying and rising again, the Holy Spirit being poured out at Pentecost, the Church being gathered, and the gospel being proclaimed to the nations. In other words, the economic Trinity is God as he reveals himself through his saving work. The immanent Trinity refers to God as he is eternally in himself. Before creation, before Abraham, before Bethlehem, before the Cross, before Pentecost, God eternally existed as Father, Son, and Holy Spirit in perfect communion and love.
Rahner’s point is that these are not two different Gods. The God revealed in salvation history is the same God who exists eternally. God is not pretending to be Father, Son, and Holy Spirit when he saves us. The Father truly sends the Son. The Son truly becomes incarnate for us and for our salvation. The Holy Spirit truly proceeds from the Father and is poured out upon the Church. The Trinity is not hidden behind the gospel. The Trinity is revealed through the gospel. This means that we do not begin with the Trinity and work our way toward salvation. We begin with salvation and discover the Trinity.
The Church did not arrive at the doctrine of the Trinity by staring into heaven and guessing. The Church arrived at the doctrine of the Trinity because it encountered the saving work of God in Jesus Christ and the outpouring of the Holy Spirit. As Christians reflected on creation, incarnation, redemption, resurrection, Pentecost, and the life of the Church, they came to understand that the God who saves is Father, Son, and Holy Spirit.
This is also why the doctrine of the Trinity and the mission of God belong together. The God revealed in Scripture is not distant, detached, or uninterested in the world. The God of Scripture is a God who seeks, rescues, restores, and reconciles. From Genesis to Revelation, the great story of the Bible is the story of God’s determination to save his beloved creation and restore his image-bearers.
The Father sends the Son. The Son sends the Church. The Holy Spirit empowers the Church.Mission is not something the Church invented. Mission begins in the very life of God.
Therefore, when we come to Trinity Sunday, we are not merely studying God’s inner life. We are beholding the God who acts for our salvation. We are confessing that the Father, Son, and Holy Spirit have been at work from the beginning, drawing humanity back into communion with God so that we might reflect his glory and participate in his life.
Only from that perspective do the Scriptures begin to open before us. Only from the standpoint of salvation do we see why the Church came to confess one God in three Persons. We know God as Trinity because God has acted as Trinity for our salvation. And that is why the doctrine of the Trinity is not a distraction from the gospel. It is the grammar of the gospel itself.
