In my many years of apologetics, the doctrine of the Trinity is a frequent subject, for obvious reasons: it is the central doctrine of the Christian Faith. However, many argue that the Trinity either isn’t true or isn’t very important because it is not explicitly mentioned in the Bible. And it is true that the word “Trinity” is not in the Bible, nor is there any passage that explicitly declares that there are three divine persons yet only one God. Yet to most Christians, the Trinity is clearly taught in the Bible, especially the New Testament. This can be seen in the fact that three distinct entities – the Father, the Son, and the Holy Spirit – are all referenced as divine, while there remains a clear emphasis that there is only one God.
How can we solve this dilemma that some say the Trinity is “not in the Bible,” yet Christians think it is “clearly in the Bible?” I think the concept of public-key cryptography can help us (please stay with me here).
Although not widely known, public-key cryptography is one of the great inventions of the 20th century. It made it possible for people to transmit information securely yet conveniently. The way public-key cryptography works is that data is encrypted by a “public key,” which anyone can see and use, but then can only be decrypted by a “private key,” which is kept secret. This allows for people to easily send encrypted information to other people, but impossible for anyone unauthorized to read it.
The secret behind public-key cryptography is what is known as a “trap-door” or “one-way” function. This is a mathematical function which is easy to perform in one direction, but very hard to compute the other direction. For example, if I give you the numbers 5,409 and 6,329, it is relatively easy for you to discover their product: 34,233,561. But if I just gave you the number 34,233,561, and I asked you to find the two factors I am thinking of, it would be very difficult to do. However, if I gave you one of those factors (say, 5,409), this would make it easy to figure out the other one. Bringing it back to public-key cryptography, the product (34,233,561) is like the public-key, and knowing one factor (5,409) is like having a private key to determine the solution.
What does this have to do with the Trinity, you ask? As we can see from history, it was a long and difficult road for the Church to define what she means by the Trinity (over 300 years, to be exact), yet once it was defined, it is easy to see how much it corresponds to the Scriptural teaching. The doctrine of the Trinity, therefore, becomes the “private key” which unlocks the teachings of the Bible regarding the Godhead. Without it, much of the teachings of the Bible on the Godhead are confusing and even at times appear contradictory. Yet with it, all the Biblical teachings on the Godhead become clear.
See, kids, math can be useful!
