Introduction to The Trinity


“You tell us that there are three gods and yet one,” the puzzled Irish said when St. Patrick was preaching the gospel to them in the 5th century AD. “How can that be?” The saint bent down and plucked a shamrock. “Do you not see,” he said, “how in this wildflower three leaves are united on one stalk, and will you not then believe that there are indeed three persons and yet one God?”1

Using this illustration from nature, St. Patrick was able to help some of the pagan Celtics to accept the doctrine of the Trinity.

I think an even better illustration of the Trinity is the universe itself (though no illustration is perfect).  Isn’t it interesting that the entire physical universe (uni = one) consists of three and only three aspects — space, time, and matter?  If you were to take away any of these three, you would no longer have a universe.

SPACE consists of length, width, and height — three in one.  If you were to take away any of these dimensions, you would no longer have space.

TIME consists of past, present, and future — three in one. If you were to take away any of these aspects, you would no longer have time.

MATTER consists of energy in motion producing phenomena — three in one.  If there were no energy, there could be no motion or phenomena.  If there were no motion, there would be no energy or phenomena.  If there were no phenomena, it would be because there was no energy or motion.2

We see this threeness in oneness composing the very fabric of the universe.  Why do you suppose the nature of the universe is so trinitarian?  Could it be that God made His universe to reflect his trinitarian nature?  I believe that God left His fingerprints on the work of His creation, and we see in it a reflection of the Trinity.

So what does the Bible teach about the Trinity? It clearly affirms the existence of three distinct Persons that are all identified as the one God of the universe.  This is not a contradiction, because we are not saying that God is both one person and three persons.  Neither are we saying that God is both one God and three Gods. We are saying that God is one in essence and three in person.  Just as the one universe exists as space, time, and matter, the one God exists as the Father, the Son, and the Holy Spirit.

The Case for the Trinity

Our belief in the Trinity does not first come from our observation of the universe, but from Scripture.  The following premises3 are all taught in the Bible, and form the basis of the doctrine of the Trinity.


“Hear O Israel, the Lord our God is One Lord” (Deut. 6:4).

“For I am God, and there is no other; I am God, and there is none like Me” (Isaiah 46:9).


“. . . God the Father . . .” (Gal. 1:1).

“. . . the Word was God. . . . The Word became flesh” (John 1:1, 14).

“. . . why has Satan filled your heart to lie to the Holy Spirit . . . You have not lied to men but to God.” (Acts 5:3-4).4


In Mark 1:10-11, Jesus is baptized, the Holy Spirit descends like a dove, and a voice from Heaven says, “You are My beloved Son, in whom I am well pleased.”  We see here that the Father, Son, and Holy Spirit could not be the same person; they are each acting in different roles at the same time.

Toward the end of His ministry, Jesus said He would ask the Father to send to us “another Helper”—the Holy Spirit (John 15:26). Do you see the three distinct persons involved in this request?


The one true God of the Bible has revealed Himself to exist in three distinct persons: Father, Son, and Holy Spirit.  God is one in nature, but three in person.

So, though the word Trinity does not appear in the Bible, the doctrine of the Trinity is based on clear Scriptural statements.

This biblical doctrine has been taught by the church since the apostles.  Below is a diagram that the church has used over the centuries to describe the Trinity.


The Doctrine of the Trinity is Essential

Some say that it is not important to believe the doctrine of the Trinity, but they are wrong to say that.  The doctrine of the Trinity underlies key teachings that are essential to the gospel.  For example, those who deny the Trinity usually deny that Jesus is God.  But if the Jesus you believe in is not God, you don’t have a Jesus who can save you!

Also, if we deny that Father, Son, and Holy Spirit are distinct, we deny God His natural personal or relational characteristics. For instance, God would not be a loving God from all eternity if He had to wait until He created in order to love anyone.  But if God is more than one person, these Persons could love one another from all eternity. It is important to believe in this relational God (who exists in self-giving  love with each other) because it affects the way we relate to one another, as well as to God.

The Father, the Son, and the Holy Spirit are Persons Living in Relationship

The Father, Son, and Holy Spirit are not impersonal entities. They each possess personhood and from eternity past have lived in personal relationship with each other. We call them persons because they live in relationship with one another.  Each member of the Trinity can refer to Himself as “I” and can communicate to another member of the Trinity as “You.” Though the Father, Son, and Holy Spirit are one God, they are distinct enough to love one another, to give to one another, to communicate to one another, and to live for one another.  This makes them Persons.


Specifically, how does the Son relate to the Father? From all eternity the Son has been the Father’s beloved and “only begotten Son” (John 3:16).  Jesus said that the Father had granted Him as Son “to have life in Himself,” just “as the Father has life in Himself” (John 5:26). The Son is eternally self-existent as God, and is of the same nature as the Father, yet His existence is from the Father.  Eternally, the Son has related to the Father as a Son, and the Father has related to the Son as a Father, though not in a physical sense.

Since the Son has eternally related to the Father as a Son, He is eternally submissive to the Father.  He functions in a subordinate role.  This is why Jesus said, “My Father is greater than I.”6

It is important to stress that Christ’s eternal submission to His Father does not in any way diminish His value as God the Son.  It is like a woman’s relationship with her husband.  A woman’s submission to her husband does not diminish her value as a person; she is equal to her husband in essence.  Likewise, though Jesus has a lower position of authority than the Father does, He is equal to the Father in his basic nature.  He is to be worshiped and glorified on the same level as the Father.  Jesus said that all should honor Him “just as they honor the Father” (Jn. 5:23).


The word used to show the relationship between the Holy Spirit and the other members of the Trinity is ‘proceeding’. In John 15:26, Jesus said that He would send to us the Holy Spirit, “which proceeds from the Father.”  Though the Spirit proceeds from the Father, He is equal to the Father and the Son, and is to be equally honored. Keep in mind that this proceeding and sending is happening between three Persons living in loving relationship with each other.


Let me emphasize that the Father, Son, and Holy Spirit have always existed in a structure of relationships.  The Father is the Head, then the Son, then the Spirit.  These three timeless and equal Persons have positions of authority based on their relationships with each other.  This structure of authority is reflected in the family and in the church.  Like the Trinity, all the members of the family and in the church have equal value, but not all have the same position of authority.


The three persons of the Trinity are not to be considered separate individuals.  The unity of their being means that they are of the same essence and that the three persons permeate one another, indwell one another, and share their attributes with one another.5 The Father, the Son, and the Holy Spirit experience mutual indwelling in a way that humans could not.

We humans are persons and individuals since we are each individual beings.6  God is three persons, yet only one being.  To help protect the biblical concept of God’s unity:

  • Don’t speak of the members of the Trinity as individuals.
  • Don’t say that there are three people in the Trinity. That makes the Father, the Son, and the Spirit sound like human individuals.
  • Don’t say there are three personalities in the Trinity, though they each have personality.
  • Don’t even say that there are three separate persons in the Trinity. Use the word distinct.  We don’t want to say anything that would imply there are three separate individuals in the Trinity.

We Reflect God’s Personhood and Relations

The Trinity (the three-personal God) is the source of our personhood.  God made us in His image as persons—having the capacity to relate to one another and to God.  We have a mind, a will, and emotions so that we can have that capacity.


After God created Adam, He said, “It is not good that man should be alone” (Gen. 2:18). Then He made Eve.   Adam was incomplete without Eve because, without her, he didn’t have some other human to relate to.  In fact, one scripture suggests that Adam and Eve together reflected God’s image: “So God created man in His own image, in the image of God He created him, male and female He created them” (Gen. 1:27). There seems to be something about the relationship between Adam and Eve that made them together reflect the image of God more than Adam would have by himself.   Think about what that means for us.  We too are not functioning as whole persons unless we are in relationship with others, as God is. We don’t necessarily have to get married like Adam did (in heaven, no one will be married, yet we will still be persons), but we do need to have fellowship with others.  When we get to heaven, we will deepen our personal relationships with God and with each other.


I want to finish this article by bringing up a wonderful comparison between the nature of God and the nature of the church.  Within both God and the church, there is unity and diversity.  According to 1 Cor. 12, the body of Christ is a unity composed of many parts functioning together for a purpose.  Can you see how the body of Christ reflects the image of God? The Apostle Paul expected all the various members of the church to grow together as one in Christ.  Paul prayed that we would

grow up in all things into Him who is the head – Christ – from whom the whole body, joined and knit together by what every joint supplies, according to the effective working by which every part does its share, causes growth of the body for the edifying of itself in love. (Eph. 4:15-16)

This verse means that all of us are to use our gifts and abilities to help each other grow together in the unity of Christ.  If your pastor ever asks you to join a discipleship group, there is a reason.  God’s will is that all of us reflect His relational nature by personally helping each other grow in grace.  There is “no holiness apart from social holiness” (as John Wesley said). Spiritual growth occurs in community (in fellowship and intimacy with other believers). This reflects the social nature of God.

If the members of the Trinity have for eternity lived in self-giving love for each other, shouldn’t we live in loving relationships with others? We were made in the image of God as social, relational beings.  Should we not then focus on others rather than ourselves?  Should we not emphasize community more than our individuality?  I believe God will bless us as we attempt more fully to reflect His triune image in our relationships with others.



  1. Encyclopedia Brittanica Online.
  2. See Trinity in the Universe, by Nathan Wood. This book was published in 1978 and reprinted in 1984 by Kriegel Publications.
  3. In a logical argument, the premises are the statements from which the conclusion follows.  In a valid logical argument, if the premises are true, then the conclusion is true.
  4. See the following two articles on the deity and personality of both Jesus Christ and the Holy Spirit.
  5. The ancient church described this interpersonal permeation as ‘perichoresis.’ Perichoresis means mutual indwelling.  There is threeness in oneness because of this mutual personal permeation.
  6. The term individual suggests singularity of being, whereas the term person (which signifies the ability to have relationship) would allow for a plurality of persons in one being. Of course, there are only three persons who are not also individuals; these persons are the three members of the Trinity. If these persons were also individuals (separate beings), there would not be one God, but three. Belief in three gods is a heresy called Tritheism.
Mark Bird
Mark Bird
Mark Bird is Professor of Theology and Apologetics at God's Bible School and College.