How It All Fits Together

The big question

After forty-three lessons, the faith might look like a long list: the Trinity, the Incarnation, grace, the sacraments, the Last Things. But the Church teaches that the faith is not a list. It is one truth, seen from many sides. How do all these teachings fit together?

What the Church teaches

Reason enlightened by faith can reach a most fruitful understanding of the mysteries, by comparing them with what we know naturally and by seeing how the mysteries are connected with one another and with our final end (Vatican I, Dei Filius ch. 4; DH 3016).

There is an order or “hierarchy” of truths, according to how each is connected with the foundation of the faith (Unitatis Redintegratio 11; CCC 90).

The central mystery of faith and life is the Most Holy Trinity, the source of all the others (CCC 234).

The Creed and the course

The Nicene Creed, said at Sunday Mass, is a summary of everything in this course:

The Creed professes	Unit
Faith in one God	1 (faith), 2 (God)
The Father almighty, Creator of all things, visible and invisible	2, 4
One Lord Jesus Christ, the only Son of God, of one substance with the Father	3, 5
Who came down from heaven for us and for our salvation	6
Who became incarnate by the Holy Spirit of the Virgin Mary, and was made man	5, 7
Who was crucified, died, was buried, and rose on the third day	6
Who will come again in glory to judge the living and the dead	11
The Holy Spirit, the Lord and giver of life	3, 8
One, holy, catholic and apostolic Church	9
One Baptism for the forgiveness of sins	10
The resurrection of the dead and the life of the world to come	11

Three chains

Pull on any one teaching and the others come with it. Here are three chains that run through the course:

1. Who Christ is. The Trinity (Unit 3) means there is an eternal Son. Because the Son became man as one divine Person with two natures (Unit 5), Mary is truly Mother of God (Unit 7). And because she is Mother of God, God prepared her by the Immaculate Conception and honoured her by the Assumption (Unit 7). Every Marian dogma is really a teaching about Christ, and every teaching about Christ rests on the Trinity.

2. How we are saved. The Fall wounded human nature and lost the grace God intended (Unit 4). Christ, true God and true man, restored it by his Cross and Resurrection (Units 5–6). That salvation reaches each person by grace (Unit 8), given through the sacraments (Unit 10), above all Baptism and the Eucharist. Remove any link and the chain breaks: without the Fall, no need of a Redeemer; without the Incarnation, no Redeemer able to save; without grace and the sacraments, no way for his work to reach us.

3. Where it all leads. The Church is Christ’s Body (Unit 9), fed by the Eucharist, in which Christ is truly present (Unit 10). The Eucharist is a foretaste of heaven, where we will see God face to face (Unit 11), and the pledge of the resurrection of our bodies (Unit 11). And heaven is nothing other than sharing the life of the Trinity (Units 3 and 11), where the course began.

How theologians explain it

One truth, many facets. St Thomas Aquinas taught that all of theology is about God, and about creatures only as they come from God and return to him. That is why his Summa moves from God (part I), to the human journey back to God (part II), to Christ, the way by which we return (part III). This course follows the same arc.

Theology leads to prayer. The site’s homepage quotes Aquinas: theology is taught by God, teaches of God, and leads to God. Near the end of his life, after an experience at Mass, Aquinas stopped writing, and is reported to have said that everything he had written seemed like straw compared with what he had seen. Theology is not the goal. It is a way of knowing God better in order to love him more.

What this course left out. Two great areas of theology were deliberately left aside: moral theology, how to live as a Christian, and spiritual theology, how to pray and grow in holiness. Both build directly on what you have learned. The tracts on Moral Theology and Spiritual Theology on this site are the natural next steps.

Philosophy bridge

Throughout the course, philosophy has been a tool for stating the faith precisely: nature and person for the Trinity and the Incarnation, substance and accident for the Eucharist, the soul as form of the body for the resurrection, act and potency for God’s existence. Vatican I’s point is that faith and reason, both from the same God, work together. Students who go on to study the philosophy course in depth will find their understanding of the faith deepening with it.

Capstone tasks

These tasks replace the usual questions. Choose one, or your teacher may set one.

1. The Creed map. Take each line of the Nicene Creed and write two or three sentences explaining what it means, citing the lesson that teaches it.

Guidance

Use the table above as a starting point. For each line, give the teaching in your own words and name one source: a council, a passage of Scripture, or the Catechism.

2. Build a chain. Choose any two doctrines from different units and explain, step by step, how one leads to the other.

Guidance

For example: from original sin (4.4) to infant baptism (10.2); from the hypostatic union (5.3) to the communication of idioms and “Mother of God” (7.1); from the soul as form of the body (4.3) to the resurrection (11.4).

3. Explain it to a friend. Write 500 words explaining to a friend who is not Catholic which teaching in this course you find most important, and why. Include one thing the Church does not claim about it.

Guidance

Aim for clarity, not length. A good answer states the teaching precisely, gives its source, explains why it matters, and corrects one common misunderstanding.