One of the major stumbling-blocks to understanding the Trinity is the lack of a really satisfactory way of explaining it. The philosophical arguments of the early Church theologians can seem either esoteric or rather less than convincing. For ordinary believers, there are many analogies and illustrations in common use, but they all work only at a very basic level. Probe a little deeper, and they break down.
The Trinity is like an egg – in that an egg has three components: the shell, the white and the yolk. But that’s where any similarity ends, because the three parts have nothing else in common with one another.
The Trinity is like water – which can exist in three forms (ice, liquid water, and steam). But there are two major problems with this analogy: firstly, you never (normally) get all three forms existing together; and secondly, water can change from one form into another. This is a really good illustration of modalism, but not of the Trinity.
The Trinity is like a shamrock leaf (or a three-legged stool) – which conjures up a mental image of God as a ‘lump’ with three identical ‘bits’ sticking out in different directions. It gives no hint of the differences between the three Persons, or of their dynamic interrelationships.
The Trinity is like a person – in that I can be different ‘people’ simultaneously (a mother, a wife and a daughter). This is an improvement on the previous inanimate examples (at least it is ‘personal’!), but it is really describing the different roles of one person – roles that have meaning with respect to other individuals in my family, but not to one another.
Many of us find these illustrations helpful, despite their shortcomings. They are not wrong, as long as it is acknowledged that they are not the whole story. But because they do not relate directly to what we read in the Bible, some people still regard the whole idea of the Trinity with suspicion.
What the Bible does tell us is that the nearest equivalent of God on earth is a human being; we are made “in God’s image” (Genesis 1:26,27). So it seems obvious that if we are going to get any sort of grasp, however imperfect, of God’s nature, then the nature of Man might be the best place to start looking.
How can ‘one’ be ‘three’?
One way in which the Bible speaks of the three ‘members’ of the Trinity is as God, the Word of God, and the Spirit of God. Now I (as a human being) also have a ‘word’ and a ‘spirit’. My ‘word’ is in my consciousness, which is verbal in content. I think in words: they are both what my conscious mind is composed of, and also its product. So, although in one sense they are ‘me’, they are also distinct from ‘me’. If I write them down, they can take on a separate, physical existence from me (as ink-marks on paper).
I also have a spirit, which permeates everything I say and do and which can influence people around me even when I am absent from them. It is a little harder to define than my words, but it is manifested (for example) in my non-verbal communication – my body language and tone of voice. My mood, my values, and my feelings are all part of it. Once again, it is an essential part of ‘me’, but it can be distinguished both from ‘me’ and from my ‘words’. Yet all three are very closely related, and for practical purposes are often inseparable. When I am speaking to you, you experience ‘me’ and get to know ‘me’ through the communication of my words and my spirit. But probably you will not consciously separate them out; you will be aware only that you are listening to ‘me’.
In the same way, God would not be God without His Word and His Spirit, and they do not exist without Him. And yet, although they are God, they are also distinct from Him: “The Word was with God, and the Word was God.” (John 1:1) When He communicates to us through His Word and His Spirit, we can distinguish between them – and yet, because they are expressed together, it is also difficult at times to separate them.
The important (and rather astounding) difference between the human and the divine is that when God’s Word was ‘written’ into physical existence and “became flesh” (John 1:14), it was as a Person – and that Person related to God as a son relates to his father. Not only is God a Person, but His Word and His Spirit turn out to be Persons as well! Which brings us to the next question:
How can ‘three’ be ‘one’?
Looking at humankind from a different angle, Genesis 1 tells us that what was created ‘in God’s image’ was ‘male and female’ – a couple. Adam alone could not be in God’s image – this is one reason why it was “not good for the man to be alone.” (Genesis 2:18) He was incomplete until Eve was created (and note that, in the story, she was created out of Adam – indicating that, although a different gender, she shared the exact same nature). Here were two individuals, the same and yet different, maintaining their individuality and yet united together in harmony, as “one flesh” (Genesis 2:24). So ‘two’ can be ‘one’ – it happens around us, all the time, whenever a man and woman grow close together in marriage. Why then (in the case of God) can ‘three’ not also be ‘one’?
Three AND one?
As these illustrations show, the hardest thing about explaining the Trinity is trying to combine the ‘oneness’ and the ‘threeness’ of God. It’s rather like the famous optical illusion, where one simple picture can be either a vase or two faces; it’s virtually impossible for the brain to perceive both interpretations simultaneously, so the best it can do is ‘flip’ from one to the other. And yet we know that both ways of seeing the picture are valid, and nobody would dream of finding that a problem. The Trinity IS a paradox – but paradoxes crop up in other areas of life too, and we manage to live with them. One example is the nature of light: when I studied physics, I was taught that neither the wave theory nor the particle theory could fully explain its strange properties. There are times when we have to admit that our knowledge and our understanding are incomplete, in theology as well as in science.