The Trinity Explained
Westminster Confession of Faith
Chapter 2, section 3: In the unity of the Godhead there be three persons, of one substance, power, and eternity; God the Father, God the Son, and God the Holy Ghost. The Father is of none, neither begotten, nor proceeding; the Son is eternally begotten of the Father; the Holy Ghost eternally proceeding from the Father and the Son.
Westminster Larger Catechism
Question 8: Are there more Gods than one? A. There is but one only, the living and true God.
Question 9: How many persons are there in the Godhead? A. There be three persons in the Godhead, the Father, the Son, and the Holy Ghost; and these three are one true, eternal God, the same in substance, equal in power and glory; although distinguished by their personal properties
Question 10: What are the personal properties of the three persons in the Godhead? A. It is proper to the Father to beget the Son, and to the Son to be begotten of the Father, and to the Holy Ghost to proceed from the Father and the Son from all eternity.
Introduction
The Bible teaches there is only one living and true God who exists as three persons, yet one being. This is commonly called the doctrine of the Trinity (Three in unity). The three persons are called the Father, the Son and the Holy Spirit. These three persons equally share one divine essence (substance) and, because they equally share the same essence, they also equally share all of the divine perfections (attributes) of that spiritual essence. They are equal in power and glory. However, there are some attributes that are not shared among the persons of the Godhead. These are the personal attributes that distinguish the Father, Son and Holy Spirit from each other.
Only one living and true God
The Holy Bible is explicit. There is only one living and true God.
“Ye are my witnesses, saith the LORD, and my servant whom I have chosen: that ye may know and believe me, and understand that I am he: before me there was no God formed, neither shall there be after me.” (Isaiah 43:10)
“Fear ye not, neither be afraid: have not I told thee from that time, and have declared it? ye are even my witnesses. Is there a God beside me? yea, there is no God; I know not any.” (Isaiah 44:8)
“Remember the former things of old: for I am God, and there is none else; I am God, and there is none like me…” (Isaiah 46:9)
“But the LORD is the true God, he is the living God, and an everlasting king: at his wrath the earth shall tremble, and the nations shall not be able to abide his indignation.” (Jeremiah 10:10)
(See “How Can I know God Exists”)
The title “Living and True” implies that all other so called gods are not gods at all. The Bible figuratively calls civil authorities gods (John 10:34; Psalm 82:1-2, Exodus 22:28) because they exercise the authority of God in the administration of the Civil Law. Angels are called gods (Psalm 97:7-9 compare Hebrew 1:6) because of their “exalted excellence”. The devil is called the god of this world (2 Corinthians 4:4) because unredeemed mankind knowingly or unknowingly serves him as their god. We are warned that fallen angels (Devils) can pretend to be gods (1 Corinthians 10:20). None of these so called gods (1 Corinthians 8:5) have the divine nature. Only the living and true God has the divine perfections (attributes) and performs the Divine Works that distinguish him from all so called gods.
One Divine Essence
Westminster Larger Catechism
Question 7: What is God? A. God is a Spirit, in and of himself infinite in being, glory, blessedness, and perfection; all-sufficient, eternal, unchangeable, incomprehensible, everywhere present, almighty, knowing all things, most wise, most holy, most just, most merciful and gracious, long-suffering, and abundant in goodness and truth.
There is one being who is the living and true God. This God is a spirit, infinite, eternal, and immutable in his being as well as in all other perfections. God is not material. The material is finite, temporal, and mutable. His spiritual essence is infinite, which means it is without bounds and thus has the quality of being everywhere present. As an eternal spirit, He is timeless, uncreated, without beginning and without end. God’s divine essence is also unchanging (immutable). Everything He created changes, He does not. He does not grow in wisdom, knowledge, power, etc.; nor do any of his perfections diminish. These three attributes also apply to all other attributes of God. He is infinite, eternal, and unchanging in his “power, knowledge, wisdom, goodness, and truth”, etc. He is the only Supreme being. He has all the qualities that make a being great--infinitely, eternally and unchangeably so.
The Persons of the Godhead
Westminster Larger Catechism
Question 11 How doth it appear that the Son and the Holy Ghost are God equal with the Father? A. The scriptures manifest that the Son and the Holy Ghost are God equal with the Father, ascribing unto them such names, attributes, works, and worship, as are proper to God only.
While Scripture explicitly teaches there is but one living and true God. The Bible also teaches there are three Persons who equally share the divine spiritual essence. These three persons are called God the Father, God the Son, God the Holy Spirit. These three are one God; not three gods. They are one God because they equally share one spiritual essence, not three separate spiritual essences. Their unity is found in their shared being. They are three persons in one being, not three persons and three beings. God is a Tri-personal being.
The Father is God
It is not generally disputed that God the Father is the living and true God.
Paul opens his letters to the Romans and the Corinthians with a clear statement that God is our Father
“To all that be in Rome, beloved of God, called to be saints: Grace to you and peace from God our Father, and the Lord Jesus Christ.” (Romans 1:7)
“Grace be unto you, and peace, from God our Father, and from the Lord Jesus Christ.” (1 Corinthians 1:3)
Jesus tells us to pray to God as our Father.
“After this manner therefore pray ye: Our Father which art in heaven, Hallowed be thy name.” (Matthew 6:9)
Jesus also calls the living and true God his Father
“For whosoever shall do the will of my Father which is in heaven, the same is my brother, and sister, and mother.” (Matthew 12:50)
The Holy Spirit is God
The Bible teaches that the Holy Spirit is also the living and true God. Peter explicit states that the Holy Spirit is God.
“But Peter said, Ananias, why hath Satan filled thine heart to lie to the Holy Spirit, and to keep back part of the price of the land? 4 Whiles it remained, was it not thine own? and after it was sold, was it not in thine own power? why hast thou conceived this thing in thine heart? thou hast not lied unto men, but unto God.” (Acts 5:3)
Notice that Peter declares that lying to the Holy Spirit is lying to God. He also is saying that the Holy Spirit is a person and not just a "force." You can not lie to a impersonal force. You can only lie to a person.
Jesus is God
The Bible also teaches Jesus is the living and true God. We know Jesus is also God because scripture applies to Jesus names, tiles, attributes, works, and worship that are appropriate for God alone. God is eternal, Jesus is the eternal “Word” (John 1:1). God is the creator and sustainer of all things; Jesus is the creator and sustainer of all things (John 1:1-3, Colossians 1:16-17, Hebrews 1:3). God is all knowing; Jesus is all knowing (Colossians 2:3). God is everywhere present; Jesus is everywhere present (Matthew 18:20). And so forth.
(See: "The Divinity of Jesus")
Tri-unity: Three persons, One Being
The Bible teaches there is but one Living and True God. The Bible also teaches that the Father is the living and true God, the Son is the living and true God, the Holy Spirit is the living and true God. The explanation for this apparent contradiction is given by John.
“In the beginning was the Word, and the Word was with God, and the Word was God.” (John 1:1)
Jesus declares:
“I and my Father are one.” (John 10:30)
“Believest thou not that I am in the Father, and the Father in me? the words that I speak unto you I speak not of myself: but the Father that dwelleth in me, he doeth the works.” (John 14:10)
According to Jesus and John there is one way that Jesus and the Father are distinct and another way in which they are one. They are distinct as Persons and yet one as to being (spiritual essence). We know this because the attributes of the spiritual essence of Living and True God are applied by the Bible to the Father, Son and Holy Spirit equally; and Personal attributes individually.
The Distinguishing Attributes and Works
The way the Bible teaches us that the person of the Father, the person of the Son, and the person of the Holy Spirit are all the Living and True God is by attributing the same divine attributes and works to all three Persons.
There are however some attributes and works that are peculiar to each person of the Godhead.
Westminster Larger Catechism
Question 10: What are the personal properties of the three persons in the Godhead? A. It is proper to the Father to beget the Son (Hebrews 1:5-8), and to the Son to be begotten of the Father (John 1:14-18), and to the Holy Ghost to proceed from the Father and the Son from all eternity (John 15:26, Galatians 4:6).
Here is an example of the works that separate the Persons of the Triune God. The Father Elects (John 6:37-39), the Son redeems (Ephesians 1:4-7), the Holy Spirit applies the benefits of Christs redemption (John 3:6-8).
One last clarification
The Persons of the Godhead are three distinct persons; not one God filling three roles as Father, Son and Holy Spirit; at one-time God acts as the Father, then another time God acts as the Son, and another time He acts as the Holy Spirit. We know there are three distinct Persons because the Bible explicit states it, the three persons communicate with each other, and manifest themselves at the same time.
In John 1:1 he explicit tells us that the Word and God were two distinct persons, yet one.
“In the beginning was the Word, and the Word was with God, and the Word was God.” (John 1:1)
There are numerous passages in which Jesus prays to the Father and the Father speaks to the Son.
“And I will pray the Father, and he shall give you another Comforter, that he may abide with you forever; 17 Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you.” (John 14:16)
In Matthew we have all three of the persons of the Godhead present at the same time. We have Jesus the Son, the Holy Spirit in the form of a Dove and the Father speaking from heaven.
“And Jesus, when he was baptized, went up straightway out of the water: and, lo, the heavens were opened unto him, and he saw the Spirit of God descending like a dove, and lighting upon him: 17 And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased.” (Matthew 3:16)
Conclusion
There are three persons in the Godhead, the Father, the Son and the Holy Spirit. These three are the one living and true God. They are not three gods. They are not three beings. They are three personalities subsisting in one eternal, infinite, immutable spiritual essence.