After looking at the Symbol of Faith (the Creed), we now begin to look at one of the most important dogmas of the faith, the Holy Trinity (the other fundamental doctrine, the Incarnation, will be covered at a later date). In modern society, dogma is considered a negative thing. It is said that a dogma is something which restricts freedom of thought, that an authority imposes on people to bind them. However, this is not the case. A dogma is a teaching which originates in the life experience of the Church. This is not the experience of church leaders who impose this teaching on everyone else. No, the Holy Spirit leads the entire people of God to express in words this fundamental experience.
The doctrine of the Trinity proclaims that God is one in substance or essence and three in persons, the Father, the Son and the Holy Spirit. This does not mean that there are three gods or that the divine essence is divided into three parts, or that sometimes God wears the mask of Father or Son or the Holy Spirit. Each person of the Trinity is completely and always God.
We might ask ourselves how this teaching arose. In the Old Testament, the first part of the Bible, we see God sending prophets to the Jewish people to teach them that there is only one, true God and one should worship only Him. As we see in the Old Testament, the Jewish people were tempted to fall into polytheism, the worship of many (false) gods. This is what the pagans who surrounded the Israelites did and the Jews frequently fell into this error. It took centuries for the prophets sent by God to teach the Jewish people that there ws only one God.
By the time Jesus Christ appeared, the Jews were finally set on a belief in the one, true God. The Jews maintained this teaching even in the face of persecution and martyrdom. Jesus, of course, believed in the one God whom he called Abba, or dear father and the apostles did also.
So how did this idea that God was one and also three arise? It is from the experience of the Apostles. For example, we see that Jesus Christ said he had the authority to forgive sins, a divine authority. Jesus demonstrated His possession of this right though his miracles and healings. We see that Jesus calmed storms at sea, worked many healings and even raised people from the dead. Jesus regularly addressed God as Abba. Abba is an Aramaic word meaning something like dear father. It was a term that Aramaic speakers used to express their love and closeness to their own fathers. The Jews never used this world to address God because they felt it wasn’t respectful enough. This is the word that Jesus used to pray to the Father, showing that He was claiming a sonship unique to Himself. And of course, Christ rose form the dead.
All of the above-mentioned things shows that Jesus Christ had a unique relationship to God.
Of course, the Apostles were devout Jews, ready to die for their belief in the one God so it took a while for them to truly recognize who Christ really was.
At first they called Jesus teacher or rabbi or prophet. They began to realize that these title were not adequate to express their experience of Jesus Christ. They began to call him Son of God. But even then they didn’t fully realize what this meant. The Apostles finally recognized who Jesus was after the Resurrection when we see St. Thomas address Jesus as “my Lord and my God”. Even at that, it took the Church centuries to learn how to express the belief that God is one, but also three. But this dogma is rooted in the Church’s experience of God.