Is There a God?
Belief in God is not a leap in the dark: the existence of a changing, caused, ordered world, and the longing of our own hearts, point to a first source of everything, whom we call God.

What this lesson teaches
- The Church teaches that reason can know God exists from the world and from the human heart.
- Aquinas's Five Ways reason from change, causes, contingency, degrees of goodness, and order to a first source of all.
- These arguments ask why anything exists at all, a question science by its nature does not answer.
- Arguments open the door; faith is still a free and personal answer to God.
Catechism paragraphs this lesson cites
- CCC 31-36
- CCC 286
CCC means the Catechism of the Catholic Church. Saints Light teaches it in its own words and never quotes it. Look up any paragraph in a printed copy or at vatican.va. See every lesson by paragraph in the Catechism index.
Scripture read in this lesson: Romans 1:20; Wisdom 13:5.
A sample question from this lesson
What does the Church teach about knowing God by reason?
- Reason can know with certainty that God exists, even without revelation
- Reason is useless, so God can be known only by blind faith
- Reason can prove every truth of the faith, including the Trinity
- Reason and faith are unrelated, so the question does not matter
Show the answer
Reason can know with certainty that God exists, even without revelation. The lesson explains that human reason can come to know God's existence from the world and the human person (CCC 36, 286), though revelation tells us much more.
The lesson in the app has three questions, each with an explanation.
Words to know
- Five Ways
- St Thomas Aquinas's five short arguments that reason from features of the world (change, causes, contingency, degrees, order) to God.
- Contingent
- Able not to exist; depending on something else for its existence.
More terms in the Catholic glossary. More passages in the Scripture index.
Read the full lesson in the app
"Is There a God?" is lesson 1 of Answers to Hard Questions. In Saints Light you get the whole teaching, the Scripture quoted in full, all three questions and a step to live it this week.
Every course is open free for your first 14 days. After that, one payment of $14.99 unlocks every course. There is no subscription.
Related lessons
- Revolutions, Vatican I and the Modern Popes (Church History)