God who is the Trinity

Choose an option and you are told at once whether it was right. The answer and the reason wait behind “Show the answer”.

A watercolor of a lamb sitting and looking up at three overlapping circles of yellow, pink, and blue meeting in one white light

Which single sentence states the doctrine of the Trinity most correctly?
1. God is one, and is three persons — the Father, the Son, and the Holy Spirit
2. There are three gods, and they get on perfectly well with one another
3. God is one, and appears in three different forms according to the occasion
4. Only the Father is truly God, and the Son and the Holy Spirit are creatures he made
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Answer ① God is one, and is three persons — the Father, the Son, and the Holy Spirit
One nature, three persons. The second answer is tritheism, the third is modalism, and the fourth is Arianism — all three are explanations the Church has rejected.
Catechism of the Catholic Church 253-256
How do “person” and “nature” differ?
1. “Person” points to what something is, and “nature” to who someone is
2. “Person” points to who someone is, and “nature” to what something is
3. They are two translations of one and the same word
4. “Person” is used only of human beings, “nature” only of God
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Answer ② “Person” points to who someone is, and “nature” to what something is
What answers “Who are you?” is the person; what answers “What are you?” is the nature. In God there are three answers to “who” and only one to “what”.
Catechism of the Catholic Church 252
The Trinity is a truth that human beings can work out by reason alone.
1. Yes
2. No
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Answer ② No
Reason can reach as far as knowing that God exists, but that God is a Trinity is a mystery of faith, known to us only because God has revealed it.
Catechism of the Catholic Church 237
What is it that distinguishes the three persons from one another?
1. Degrees of divinity — the Father is the greatest of the three
2. The work each is given — the Father only creates, the Son only saves, the Holy Spirit only makes holy
3. Their relations to one another — begetting, being begotten, and proceeding
4. The age each appeared in — the Father in the Old Testament, the Son in the Gospels, the Holy Spirit ever since
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Answer ③ Their relations to one another — begetting, being begotten, and proceeding
What sets the persons apart is neither rank nor period of history but relation. Miss the third answer and you slide either into subordinationism, where one person is less God than another, or into modalism, where one God merely changes masks.
Catechism of the Catholic Church 254-255
The Son is a creature made by the Father.
1. Yes
2. No
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Answer ② No
The Son was not made but begotten. This is the very point the Nicene Creed nails down: “begotten, not made, consubstantial with the Father”.
Catechism of the Catholic Church 242, 262
Who is the one who “proceeds from the Father and the Son”?
1. The Son
2. The Blessed Virgin Mary
3. An angel
4. The Holy Spirit
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Answer ④ The Holy Spirit
The phrase points to the procession of the Holy Spirit. The Western Church calls it the Filioque, Latin for “and the Son”, and added it to the Creed; that clause became a long-running point of dispute with the Eastern Church.
Catechism of the Catholic Church 245-248
What does the principle that “everything God does, the three persons do together” mean?
1. The three persons settle on an order and take turns at working
2. In fact only one person works and the other two look on
3. God's action toward what is outside him is undivided, yet what is proper to each person shows through in it
4. Each kind of work has its own person in charge, and none of them crosses into another's
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Answer ③ God's action toward what is outside him is undivided, yet what is proper to each person shows through in it
Creation, salvation, and sanctification alike are the common work of the three persons. Attributing creation to the Father, salvation to the Son, and sanctification to the Holy Spirit is a way of speaking that brings out what is proper to each person.
Catechism of the Catholic Church 258
When a Christian is baptized, whose name is called upon?
1. The name of the Father and of the Son and of the Holy Spirit
2. The name of Jesus Christ alone
3. The name of the Church and the apostles
4. The name of the priest who baptizes
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Answer ① The name of the Father and of the Son and of the Holy Spirit
The words of baptism are themselves a profession of faith in the Trinity. That is why baptism is called the door through which we enter the faith of the Trinity.
Catechism of the Catholic Church 232-233
The Old Testament makes plain that God is one, and so prepares the way for the revelation of the Trinity.
1. Yes
2. No
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Answer ① Yes
Yes — but only as a preparation. The Trinity was fully made known through the Incarnation of the Son and the sending of the Holy Spirit.
Catechism of the Catholic Church 237, 684
What goes wrong if you explain the Trinity by saying “just as water becomes ice, water, and steam, God becomes three forms”?
1. It erases the fact that the three persons are there all at once, and so comes out as modalism
2. The explanation is too hard to follow
3. Water is never mentioned in Scripture
4. Nothing is wrong with it — it is a good analogy
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Answer ① It erases the fact that the three persons are there all at once, and so comes out as modalism
Nothing can be ice and steam at the same moment, so the analogy turns the three persons into forms that follow one another in time. The baptism of Jesus, where the voice of the Father and the descent of the Holy Spirit come together, is what brings that explanation down.
Catechism of the Catholic Church 254, 535
Why is the line “God is love” bound up with the Trinity?
1. Because God had someone to love only after making human beings
2. Because the word “love” appears in Scripture more often than any other
3. Because it is really a separate subject with no bearing on the Trinity
4. Because love is given and received, and that giving and receiving is already there within God
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Answer ④ Because love is given and received, and that giving and receiving is already there within God
If God were solitary, there would have been no one for God to love before the world was made. Because there is a communion of three persons, God is love in himself.
Catechism of the Catholic Church 221
What does the Trinity most properly mean for the life of a believer?
1. It is a theory you only need to memorize and keep in your head
2. It is a rule that you bow three times when you pray
3. It is a call to be drawn into the communion of God and to live in communion with other people as well
4. It is material only those going to seminary need to know
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Answer ③ It is a call to be drawn into the communion of God and to live in communion with other people as well
The Trinity is not a riddle to be solved but an invitation. The communion of the Father, the Son, and the Holy Spirit is both the source and the pattern of communion within the Church.
Catechism of the Catholic Church 260, 850