Previous article in this series: November 15, 2010, p. 92.

Heidelberg Catechism, Lord’s Day 8 

Question 24. How are these articles divided? 

Answer. Into three parts: the first is of God the Father and our creation; the second of God the Son and our redemption; the third of God the Holy Ghost and our sanctification. 

Question 25. Since there is but one only divine essence, why speakest thou of Father, Son, and Holy Ghost? 

Answer. Because God hath so revealed Himself in His Word, that these three distinct persons are the one only true and eternal God.

A Foundational Truth

Among all the religions of the world, the Christian faith is unique. Every other religion has a god or gods who are the product of human imagination, and are therefore limited, but the God of the Bible is infinite in every way, and far beyond our comprehension as men. Our knowledge of who God is comes from God Himself. It is especially the doctrine of the Trinity that sets Christianity apart and that shows the greatness of our God.

The doctrine of the Trinity is basic and central to all other Christian doctrines. This is evident in the Apostles’ Creed, which is divided into three parts according to the three persons of the Godhead. Under these three divisions the Creed treats all the essential teachings of the Bible that every true Christian believes. The Heidelberg Catechism attributes the whole of our existence and salvation to the triune God (God the Father and our creation, God the Son and our redemption, and God the Holy Spirit and our sanctification).

In its early history, the church laid the foundation for all subsequent development and understanding of doctrine by struggling with and clearly defining the biblical doctrine of the Trinity. The key issue at stake in these early controversies was the question of salvation. As we saw in Lord’s Days 5 and 6, our salvation is possible only if the Mediator is true God, a real man, and yet sinless. The doctrine of the Trinity affirms the divinity of Christ. Thus, the doctrine of the Trinity is central to the gospel and essential for our salvation.

The Trinity in the Bible

The doctrine of the Trinity is progressively revealed in the Scripture. That is, God did not reveal everything about Himself as triune God immediately in 
Genesis 1, but over a long period of time, as men grew in their understanding of God, He gave a greater and more full revelation of Himself. The Bible puts it like this, “God who at sundry times and in divers manners spake in times past unto the fathers by the prophets, hath in these last days spoken unto us by his Son” (Heb. 1:1-2).

This is not to say that the doctrine of the Trinity is not taught in the Old Testament. In fact, from our New Testament perspective, we even see it in God’s conversation with Himself in Genesis 1:26, “Let us make man in our image, after our likeness.” And there are many other things that show God as triune—for example, the appearances of “the Angel of the Lord,” who is identified as God, yet distinct from God. However, in the Old Testament, while the church on earth was still in its infant years, God emphasized that He is the only God; then later He came in the person of His Son, Jesus Christ; and still later, as He brings the church to maturity, He comes in the person of the Holy Spirit.

The word “Trinity” is not found in the Bible but is, nevertheless, an accurate description of what the Bible teaches. It is simply the compound of two words: “tri,” which means three, and “unity,” which refers to oneness.

There are three elements to this truth.

First, the Bible teaches that there is only one being that we may call God. There is only one God. Deuteronomy 6:4: “Hear, O Israel: The Lord our God is one Lord.” Isaiah 43:10: “Before me there was no God formed, neither shall there be after me.” And then in the New Testament (Gal. 3:20): “God is one.” Jehovah exclusively has the right to be called God.

Second, the Father, the Son, and the Holy Spirit are distinct from one another. We say that each of them is a person, that is, each of them has characteristics and activities unique to Himself, in distinction from the others. In the being of God, the Father begets the Son, the Son is begotten of the Father, and the Holy Spirit proceeds from the Father and the Son. They are also distinct in their revelation outside of the being of God. Only of the Son can it be said that He became flesh, not of the Father and Spirit. The Spirit’s unique work is to regenerate and save the elect children of God. The Bible shows their distinctness from one another at the baptism of Jesus, when the Father spoke from heaven, the Son who had become man was baptized, and the Holy Spirit descended in the form of a dove.

Third, each of the three are identified in Scripture as God, and so the three together form the one being of God.

That the Father is God is the plain teaching of Scripture and has rarely been disputed.

Romans 9:5 says that Jesus who came in the flesh “is over all, God blessed forever, Amen.” Hebrews 1:8 says of Him, “Thy throne, O God, is for ever and ever.” John 1 identifies Him as the eternal Word, who was God and who made the worlds, and who became flesh.

To the Spirit are ascribed divine characteristics. In Hebrews 9:14 He is referred to as “the eternal Spirit.” The Spirit was the person of the Godhead who effected the conception of Jesus in the womb of the virgin Mary (Luke 1:35). And Peter tells Ananias that his lie was “to the Holy Ghost…not…unto men, but unto God” (Acts 5:3-4).

These three persons constitute the one being who is God. These three agree in one. There is a perfect harmony in the Godhead. The will and work of the three are always harmonious. The Son does not have a different purpose than the Father, nor does the Spirit than the Son.

There is mystery here, but not contradiction. God is not one in the same way that He is three, but He is one in being and three in persons. The mystery of the Trinity is this, that God is beyond our comprehension and searching. We know Him only through His revelation, and we believe His revelation only by faith.

The Importance of the Trinity

Often we do not appreciate this important doctrine as we should. It can seem complicated and abstract, and so we spend little time meditating on it, and praising God as triune. However, if we really think about it, this truth is the foundation for all our praise of God, and it is very practical for our lives.

For example, the doctrine of the Trinity helps us with our worship of God. It teaches us the uniqueness of our God, and that He alone must be worshiped. It shows us the depth and incomprehensibility of God. It shows us that we owe a constant and eternal debt of praise to Him. It ought to humble us as we realize our limitations before Him.

This doctrine also shows us what worship is. In the Trinity, God enjoys a rich and perfectly harmonious life of covenant friendship. In worship, God draws us into fellowship with Himself. This doctrine also shows us that in God we have all that we need for salvation. God is our Father in heaven on whom we can depend as His children, and who will hear us when we pray. Jesus is our Savior who, as God, has paid the infinite debt of our sin, but who also is now an understanding and sympathetic king and ruler over all things for our sakes. The Holy Spirit is the one who comes and works in our hearts and lives, and by His irresistible power saves us to the uttermost.

Finally, and perhaps most importantly, the covenant life of God as Trinity shows us how rich and warm He is as God. There is a diversity of persons, yet a perfect unity. The Son dwells eternally in the bosom of the Father (John 1:18). God is a family God. And in salvation, He brings us into His own family, so that we are the “household” of God. This becomes the foundation for our living together, in the church as well as in our Christian families, in harmony and love.

Do you believe in God triune? “Whosoever denieth the Son, the same hath not the Father: but he that acknowledgeth the Son hath the Father also” (I John 2:23). Those who do not know and believe in this triune God do not have and know God but only an idol of their imagination. The way of salvation is to believe in God and believe also in His Son, who is God, the only way to the Father.

Questions for Discussion 

1. How many Gods are there? Prove this from Scripture. What does this mean for worship? 2. Who are the three persons of the Godhead?

3. Give some evidence of the triune nature of God from the Old Testament. Do you think the saints of the Old Testament could understand this?

4. What does the baptism formula of Matthew 28:19teach us about each of the persons of the Trinity?

5. From Scripture, prove the divinity of the Son.

6. Why is it important that we confess that Jesus is God?

7. Why did the Jews want to kill Jesus, according to John 5:18 and John 10:30-33?

8. How would you answer a Jehovah’s Witness or a Unitarian, who say that the doctrine of the Trinity is a contradiction, and so therefore must be false?

9. U se the Bible to prove that the Holy Spirit is God.

10. How does the harmony of the Trinity show the error of Pentecostalism, which separates the Spirit’s work from the work of Jesus? (SeeJohn 16:13-14.)

11. Can we say that Jesus loves all men, but the Father does not? How does the doctrine of the Trinity help to answer this question?

12. How does the doctrine of the Trinity show the warmth of the being of God? What implications does this have for salvation, for worship, for family, and for life in the church?

13. If someone does not believe in the Trinity, what kind of god are they worshiping?