The Trinity is often dismissed as being illogical using simple mathematics: 1+1+1 equals 3 not 1. This is a popular polemic against the Trinity used by Muslim apologists1.
Firstly, it is important to recognise that the doctrine of the Trinity is not the result of adding together three Gods. The teaching of the Trinity, however, is the result of recognising that Scripture witnesses that there is one God, who eternally exists as three persons in relationship with each other who are each fully God.
Secondly, it is important to remember that the universe and the world we live in is far more complicated than simple maths equations taught to young children. Interestingly on a subatomic (quantum) level, things operate in a way that seem to go against the simple rules of maths and classical physics. If this is true of the created world, how much more should we expect this to be true of the God of the universe who created all things, defined the laws of physics, and brought time into being. Although God has revealed himself to us in a way we can understand (especially in the person of the Lord Jesus), trying to reduce God's being into our limited understanding and logic will only result in idolatry.
However, on the other hand there are contexts where one can equal three. A family is a good example, a mother, a father, and a child. This is sometimes referred to as a 'compound unity' (see “In Hebrew, the word for "one" can be used to express a ‘composite’ unity” for more on this). It is interesting that this is the very example that the Bible gives at the beginning of Genesis, where it describes Adam and Eve becoming one flesh (Genesis 2:21-25). One other helpful example is the number 3. It is both a single digit, yet by very definition plural.
We should always be careful not to reduce the Trinity down to any human formula, as this will always lead to a false doctrine. The illustration of water being like the Trinity for example in that water can exist in three forms, a gas, a liquid, or a solid, is in fact a heresy called Sabellianism (a heresy taught in the 3rd Century)2. It can be helpful however to use examples like these to disarm simplistic misconceptions of the Trinity. In these situations, it is important to qualify the fact that no example of anything created can fully explain God’s nature.
It could be questioned why a doctrine so complicated and difficult to define could be the true description of God. In a debate between Shabir Ally and Nabeel Qureshi titled, “What is God Really Like: Tawhid or Trinity?”3, Ally, quoting James White, complained that “it is easy to fall into a heresy when thinking about the Trinity” commenting that believing in the Trinity is like “walking a very sharp edge between heresies”. However, the very fact that the nature of God is something beyond our understanding should comfort us that the Trinity is not something created by humans. At the same time, it is important to recognising that the doctrine of the Trinity is in fact just the result of embracing simple declarative truths about God as he reveals himself in Scripture.
It is important to understand that even Islam has apparent contradictions that Muslims cannot easily explain, like the question of the Quran being the eternal word of Allah yet something separate to him. See “Is Tawhid Logical?” for a further discussion on this.
Even though God is far beyond comprehension, it is a wonderful thing that he has made himself known to us in ways we can understand, especially in the person of the Lord Jesus. It is worth pointing out that as Christians our starting point with the Trinity is not mathematics but the person of the Lord Jesus, who we read of being both God and man, but also experience him as being Lord and Saviour. Christ is always a far better starting point when trying to ‘prove’ the Trinity rather than trying to fit the ‘maths’ of the Trinity into a logical argument.