By now, you may be thinking “You made some good points, but how do I really know the Trinity is true and not just something Christians made up? How can God be three and one at the same time? Do Christians believe in three gods? The ‘Trinity’ never appears in Scripture; how vital can it be?” Well, the next few posts are dedicated to addressing those thoughts exactly.
The quick response is “it was the result of numerous, overwhelming, clarifying encounters with God. Encounters so powerful that they could not be denied or ignored.” (Christian Hofreiter)
The challenge for the early church was that the Bible did not describe the Trinity in detail, nor did it give them any vocabulary to use. The term “Trinity” comes from the Latin term Trinitas, which means a triad, or set of three. Tertullian coined this term. He also influenced the “persons” terminology. Before you start thinking, “Well if it’s a term they made up because it’s not in the Bible, I won’t believe it”, consider discoveries in science for a moment. For example, the idea of gravitational waves was developed over thousands of years and new language had to be developed to describe the idea.
“So, much like scientists sometimes have to coin new words and put forward new ways of looking at the world in light of new insights and experiences, so the early Christians had to develop a new vocabulary to talk about the way in which God had made himself known in Jesus Christ through the Holy Spirit.” (Christian Hofreiter)
Now, remember, the orthodox belief is God is one being or essence in three persons. The “three persons” analogy allows us to discuss the Trinity, instead of the full meaning of God, which we as finite beings will never comprehend.
“For in truth, because the Father is not the Son, and the Son is not the Father, and the Holy Spirit (who is called the gift of God) is neither the Father nor the Son, then certainly there are three. But when it is asked, ‘Three what?’ then the great poverty from which our language suffers becomes apparent. ‘Three persons’ has been coined not in order to give a complete explanation by means of it, but in order that we might not be obliged to remain silent.” (On the Trinity, Augustine)
You may recall from my first post these ideas were solidified in ecumenical councils in the fourth century. At the Council of Nicea in 325 AD, it was agreed upon that Jesus Christ is of the same nature (essence, being) as God the Father. The Council of Constantinople in 381 AD confirmed the Council of Nicea and added clarifying language about the Holy Spirit. The Nicene Creed and Constantinoplean Creed can be read online.
You may wonder, “Well that happened several centuries ago. Is the doctrine up for renegotiation?” I will let Karl Barth and Alister McGrath speak to that.
“The Trinity is an insight which a church with an ear for Holy Scripture not only could reach, but had to reach at a specific time. …Divine truth is given human formulation here in a way in which it had to be formulated at some period, so that this formulation, once achieved, must never be lost or forgotten again. …Even to this day, this decision is that not merely of the Roman Catholic and Orthodox churches, but also basically of all the great Evangelical churches as well.” (Church Dogmatics, Karl Barth)
“The doctrine of the Trinity is not some arbitrary and outdated dictate handed down by some confused council. It is the inevitable result of wrestling with the richness and complexity of the Christian experience of God.” (Studies in Doctrine, Alister McGrath)