Introduction

One of the most often misunderstood beliefs that Christians hold is the idea of the Trinity. Christians themselves often find themselves at a loss as to how to adequately express their understanding (and many times simply express an incorrect view). This summary should help. There are really only two ideas that must be understood to grasp the true essence of this teaching:

• There is only one God (Dt. 6:4; Isa. 44:6; 1 Cor. 8:6; Eph. 4:6; 1 Tim. 2:5).
• There are three distinct persons (Ps. 45:6, 110:1; Isa 63:7-10; Zech 1:12; Mt. 3:16-17, 28:19; Lk. 23:46; 2 Cor. 13:14)
  that are each fully God:
  • The Father (Jn. 6:27; Rom. 1:7; Gal. 1:1)
  • The Son (Mk. 2:5; 14:61-65; Jn. 1:1-5; 8:58; 10:11; Col 1:15-17; Heb. 1:1-15; Rev. 1:17)
  • The Holy Spirit (Gen 1:2 (cf. Isa. 44:6; Isa 63:7-9; Ps. 139:7; Acts 5:3-4; 2 Cor. 13:14; Heb 9:14)
    *For more on these see the separate articles on each member of the Trinity elsehwere on this site.

So God is plurality within unity. The Father, The Son, and The Holy Spirit are each persons, and are each God, but they are not each other. Neither are there three gods (polytheism), nor is there only one person who is three different expressions of God (modalism). God is one in nature (there is only one "what"), but three in person (there are three "who's"). There is one “it,” and three “I’s.” There is one object, and three subjects. There is distinction in God without division.

Because we only find one person per essence in humanity, this is difficult to grasp, but there is no contradiction in stating that one essence is shared by three persons. Further, one member of the Trinity, Jesus, took on an additional nature at the incarnation - that of humanity. Thus, Jesus is one person with more than one nature. Again, this is not a contradiction - it is simply that in humanity we normally only see one nature per person. As the chart below illustrates, God did not "become a man" - it is rather that God in the person of Jesus Christ added the nature of humanity to the nature of deity. The two natures are not combined, nor are they separated into two beings. Rather, they are joined at the point of the person of Jesus Christ.

There seem to be all sorts of paradoxes involved with Christ being a man and God at the same time. But it must be remembered that Christ, in addition to being God, is also man - not some sort of combination. The human nature was added to the divine. Thus, what is true of human nature is true of Christ (finitude, mortality, growth, etc.), and what is true of God is true of Christ (infinitude, immortality, unchangability, etc.). Once this is understood, the paradoxes disappear.

Two Heresies to be Avoided

There are two heresies involved with the three-in-one teaching of the Trinity:

Modalism

One such heresy is Modalism, the teaching that God is one essence and one person - and that this one person only manifests in different ways. Depending on what "mode" God happens to be in at a given time we assign Him different names (Father, Son, Holy Spirit). 

This is not the teaching of Scripture because:

• The Father sent the Son. 
• The Father loves the Son. 
• Christ prayed "Not my will but yours . . . " to the Father. 
• At the baptism of Christ all three persons "manifest" themselves 

Tritheism

The other extreme we want to avoid is Tritheism, the idea that there are three persons and three essences in the nature of God - for that would equate to three gods. 

This is polytheism and is completely unbiblical.

False Analogies

Because we cannot imagine that which does not exist in nature, the true Trinity is a very difficult concept to grasp - yet we must for the Bible teaches it. Analogies are helpful ways to express that which is difficult to grasp, some are better than others and no analogy is perfect in all its parts. Unfortunately the wrong ideas presented above are sustained even in Christian circles by way of false analogies that are sometimes used in attempts to understand the truth. Here are a few (try to see which heresy is unfortunately being supported by each):

Child/Parent/Sibling: You can be a child to your parents, a parent to your children, and a sibling to your sibling;  but you are only one person. This analogy is false because God does not reveal Himself in modes of action. He is three in person - not just one who performs different roles.

Water: Think of water...it is a single element that exists in three forms (gas, liquid, solid) and each one is distinct from the other. This essentially falls into the same modal problem noted above. God does not have parts, for the only way to distinguish a part is to have a lack in one or another part, and God lacks nothing.

The Egg: Consider an egg: it is one, and yet has three parts. This one is way off, for God cannot be separated into parts. Each member of the Trinity is fully God. It is really a collection of different things. No single part of an egg is an egg, the parts must be added together to form the one.

Better Analogies

A Triangle: A Triangle is three in sides, yet it is one in shape. Each side of the triangle is necessary for its existence, each meets the other at the angles, and no sides are distinguishable. But of course no single line is the whole triangle so this is where the analogy breaks down (as all analogies do). 

Multiplication of 1: 1 x 1 x 1 = 1. Here we see three singularities equally one. This is a good example of the essence of God (but not the persons of God which would be represented by 1 + 1 + 1).

Love: Love involves the love of the lover, the love of the loved, and the love they share. This one is good because three "loves" must be present to have love.

Conclusion

Any explanation of the nature of God must account for all that the Bible teaches - not focusing on one aspect (like unity) at the expense of others (plurality). The Trinity successfully unites all that Scripture has to say about God without contradicting itself or logic. It is therefore the best way to express the nature of God as revealed in Scripture. While the Trinity is impossible to fully grasp with our finite minds, we must hold on to its principles for they are biblically sound.