Rosal

What is the Holy Trinity? Three Persons, one God, explained

The Baptism of Jesus in the Jordan River: Saint John the Baptist pours water over him from a shell while a golden light and a white dove come down from the sky

The Holy Trinity is the central mystery of the Catholic faith: there is one God, and in that one God there are three distinct Persons, the Father, the Son and the Holy Spirit. They are not three gods but one God. Each Person is fully God, and the three are equal, equally eternal and powerful. We could never have guessed it ourselves: we know it because God revealed it to us in Jesus.

What is the Holy Trinity?

Catholics believe in one God. It is the faith of Israel, which Jesus repeated: the Lord is one (Mark 12:29). But Jesus showed us more about that one God: that he is Father, Son and Holy Spirit. The Father is not the Son, the Son is not the Holy Spirit, and the Holy Spirit is not the Father: they are three distinct Persons. And yet the three are one God, with one divine nature.

What distinguishes the Persons is how they are related to one another: the Father eternally begets the Son, the Son is begotten of the Father, and the Holy Spirit proceeds from the Father and the Son. None came first, and none is more important. That is why Saint John can say that God is love (1 John 4:8). Saint Augustine put it this way: in God, from all eternity, there is the one who loves, the one who is loved, and the love that unites them.

Who are the three Persons of the Trinity?

The three Persons do everything together, because they are one God, but the Bible shows us each one with what is his own:

  • God the Father

    The First Person. He is the source of everything: the Son comes from him from all eternity, and creation comes from him. Jesus taught us to call him our Father, and showed him to us as the father who runs out to embrace the son who comes home (Luke 15:20).

  • God the Son

    The Second Person, the Father’s eternal Word. Out of love for us he became man in the womb of the Virgin Mary: he is Jesus, true God and true man, who died and rose to save us.

  • God the Holy Spirit

    The Third Person, the love of the Father and the Son. Jesus promised him and sent him at Pentecost. He makes us holy, guides us, and has lived in us since our Baptism.

Why is the Trinity called a mystery?

In the faith, a mystery is not a riddle with no answer, and not something against reason. It is a truth so great that we will never finish understanding it, though we can know it and love it more and more. The Trinity is the greatest mystery, and all the others flow from it. No one could have discovered it just by thinking: God made it known to us.

A legend says that Saint Augustine was walking on the beach, thinking about the Trinity, when he saw a child trying to pour the whole sea into a hole in the sand. It is just as impossible for our minds to hold God. What we can do is let him love us.

Is the Trinity in the Bible?

The word Trinity does not appear in the Bible: the Church began using it later to name what the Bible shows. And what it shows, we know through Jesus.

Jesus called God his Father in a unique way, said that he and the Father are one (John 10:30), and promised to send the Holy Spirit (John 14:16-17). At his Baptism in the Jordan River, all three Persons were shown: the Son in the water, the Father’s voice from heaven, and the Holy Spirit coming down like a dove (Matthew 3:16-17). And before going back to heaven, he sent the apostles to baptize in the name of the three Persons (Matthew 28:19). In the name, singular: one God.

The Church explained it in precise words at her first councils. The Council of Nicaea, in the year 325, taught that the Son is one in being with the Father, and the Council of Constantinople, in 381, that the Holy Spirit is worshiped and glorified with the Father and the Son.

How can God be three Persons?

God is one in what he is, his divine nature, and three in who he is: three Persons. He is not one and three in the same sense, so there is no contradiction, even though we will never finish understanding it. In the first centuries, some people tried to simplify the mystery, and the Church explained why it was not so. Her answers still help us avoid three mistakes:

  • They are not three gods

    The three Persons are not a team of three gods working together. They are one God, with one love, one will and one power.

  • They are not three costumes

    God is not one Person who sometimes appears as the Father, sometimes as the Son and sometimes as the Spirit. The three Persons are truly distinct, and all three exist at once, from all eternity.

  • None is greater than another

    The Son and the Holy Spirit are not creatures or second-rank gods. The three Persons are equally eternal: none of them began to exist.

When is Trinity Sunday?

The Church celebrates the Solemnity of the Most Holy Trinity on the Sunday after Pentecost. Since Pentecost depends on the date of Easter, the day changes every year, falling between mid-May and mid-June. But really we celebrate the Trinity every day: each time we make the Sign of the Cross or pray the Glory Be.

How do you explain the Trinity to children?

No comparison fully explains the Trinity, and many fall short. Water that can be ice, liquid or steam, for example, suggests a God who changes form, which is exactly the costume mistake. A tradition says Saint Patrick used a shamrock, three leaves on one plant; it works as a start, as long as you add that each leaf is only part of the plant, while each Person is all of God. The simplest way is what the Church does: say it as it is, one God in three Persons, and pray it.

With the youngest, it is enough to start with the Sign of the Cross: in it we name the three Persons, and by saying in the name, singular, we say they are one God.

As a family

Before meals or bedtime, make the Sign of the Cross slowly and let the children say whom they name with each movement: the Father at the forehead, the Son at the chest, the Holy Spirit from one shoulder to the other. Once a week, thank each Person together for something: the Father for creation, the Son for his love all the way to the cross, and the Holy Spirit for his help.

To read more, the Catechism of the Catholic Church, paragraphs 232, 233, 234, 237, 240, 242, 243, 245, 253, 254, 255, 257, 261, 266, 267.

This topic in Rosal

In the app, these lessons teach this topic:

  • “Three Persons, one God”Unit 2: God the Father and the Trinity. Taught by Saint Teresa of the Andes.
  • “God, our Father”Unit 2: God the Father and the Trinity. Taught by Saint Thérèse of Lisieux.
  • “The Holy Spirit, giver of life”Unit 2: God the Father and the Trinity. Taught by Saint John of the Cross.

Every lesson starts with a saint’s story and comes with two or three questions that give the Catechism paragraph, one small thing to do at home, and a version for children 6 to 10. Units 2 to 6 are part of Patron. Unit 1 and all 20 feast lessons are free.

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