Over the years, I’ve had plenty of questions about Scripture and issues of faith. One of the deepest questions I’ve experienced concerns the nature of God—specifically God as Trinity. I think one of the reasons for these questions is that the doctrine of the Trinity is both fascinating and mysterious.

Illustrations have been applied to assist us in explaining the Trinity: the egg (shell, yoke, white) or water (ice, liquid, steam) or a person (husband, dad, employee). These illustrations lack because they fail to justly explain the nature of God. They fall incredibly short because when we talk about the Trinity because we are talking about the nature of God himself: One God in three Persons.

The Bible affirms several truths about God’s nature as revealed in the Trinity.

First, God is One. Christianity is monotheistic. There is only one God.

“Hear, O Israel: The Lord our God, the Lord is one.”

Deuteronomy 6:4

Second, God the Father is God. Jesus teaches us to pray to God the Father as holy and Sovereign.

Pray then like this: “Our Father in heaven, hallowed be your name.”

Matthew 6:9

Third, God the Son is God. When Thomas saw the risen Jesus, he called Jesus Lord and worshipped him. Only God can be worshiped. Jesus himself affirmed that only God can be worshiped.

Thomas answered him, “My Lord and my God!”

John 20:28

Then Jesus said to him, “Be gone, Satan! For it is written, “‘You shall worship the Lord your God and him only shall you serve.’”

Matthew 4:10

Fourth, God the Holy Spirit is God. When Annanias and Sapphira lied about how much they sold their property for, Peter said they lied to God.

But Peter said, “Ananias, why has Satan filled your heart to lie to the Holy Spirit and to keep back for yourself part of the proceeds of the land?  While it remained unsold, did it not remain your own? And after it was sold, was it not at your disposal? Why is it that you have contrived this deed in your heart? You have not lied to man but to God.”

Acts 5:3-4

Fifth, God is One, yet in three persons. God is Trinity as the Father is God, the Son is God, and the Holy Spirit is God. At Jesus’ baptism, each person of the Trinity acted in the event uniquely (Matthew 3:13-17). This is an important distinction that reflects the Trinity.

In Jesus’ own baptism, there are not simply three names but three actors—the Father who speaks (“This is my beloved Son”), the “beloved Son” who is baptized, and the dove who hovers above Jesus, suggesting reference to the Sprit hovering over the waters in creation and concurring with the benediction on all that God has made.

Michael Horton, The Christian Faith, 275.

Trinitarian heresies of a variety of sorts have risen throughout church history. Arianism taught that Jesus was not God. Modalism taught that God revealed himself in different modes at different times. For example, God revealed himself in the Old Testament as Father, in the Gospels as Jesus, and now to the church as the Holy Spirit. These heresies, along with others, misconstrue the truths of the Trinity affirmed in the Bible in order to try to make sense of the Trinity. But instead of trying to wrap our finite minds around the mystery of the Trinity, we need to believe what the Bible affirms and accept that the mystery of Trinity means God is greater than we can understand.

With Augustine, we must say, “I believe in order that I may understand.” 

The Trinity is a staggeringly practical and important doctrine. Even as it may be difficult to fully understand, we can clearly understand the implications of the doctrine for our Christian experience.

Without the Trinity our salvation according to Scripture would not be possible. Take a look at Ephesians 1:3-14 and note how each person of the Trinity participates in our salvation. The Father planned our salvation, the Son accomplished our salvation, and the Spirit convicts us to salvation (John 16:8-12) and assures us of salvation.

Without the Trinity our prayers would be meaningless. We pray to the Father through the Son by the Holy Spirit. We don’t talk to the Father on the evidence of our own goodness, but we talk to the Father based on the righteousness given to us by Christ. And it is the Holy Spirit that both prays for us (Romans 8:26) and empowers our prayers.

Without the Trinity, we would not have a God who is love. When John affirmed that “God is love” (1 John 4:7), he used the Greek word agape for love. Agape is love that is other-oriented, relational, selfless. But God has always been, and there was a time when only God existed. So how could God be love? He could only be love in the definition of 1 John 4:7 if God is Trinity, existing eternally in the Persons of Father, Son, and Holy Spirit.

Tim Keller explains this concept beautifully.

If God is unipersonal, then until God created other persons there was no love, since love is something that one person has for another. This means that God was power, sovereignty, greatness from all eternity, but not love. Love then is not the essence of God, nor is it at the heart of the universe. Power is primary.

Tim Keller, The Reason for God, 225.

Be thankful that the God whose greatness and nature in Trinity is greater than our understanding, yet gracious enough to condescend to be our Savior and Friend.