Faith and Reason: How Do We Know God?

Part 5: How Do We Know God?

Up to this point, we’ve laid the groundwork. We’ve defined faith, explored reason, and clarified how they relate. Now we arrive at one of the most fundamental questions of all: Can we know anything about God? And if so, how?

The Catholic answer is a resounding yes. We can know God, but not completely. We can know something of Him by reason, and much more by revelation. Both are real. Both are trustworthy. But they are not the same.

Knowing God Through Reason: Natural Theology

Even without the Bible, a person can come to know that God exists. This is what we call natural theology. It is the use of human reason, unaided by revelation, to reflect on the world and draw conclusions about its source.

The Church teaches that certain truths about God are accessible to all people through reason alone. These include:

• That God exists

• That He is eternal, intelligent, powerful, and the cause of all things

• That He is the source of moral law

As St. Paul writes,

“Ever since the creation of the world, His invisible attributes of eternal power and divinity have been able to be understood in what He has made.”(Romans 1:20)

Classical arguments for God's existence, such as the First Cause, the argument from design, and the moral argument, all belong to this natural knowledge. They help us reason back from the effects of creation to the cause behind it.

But they only take us so far.

Why We Need Revelation

Reason can tell us that God is, but it cannot tell us who He is. We can reason that God exists, but not that He is a Trinity. We can guess that He is good, but not that He became man and died for us.

For these truths, we need something more. We need God to reveal Himself.

This is what we call revealed theology. It is the knowledge of God that comes not from our searching, but from His self-disclosure. In Christ, God speaks clearly. He does not just leave us to ponder the universe. He comes to us and says, “Here I am.”

Faith Responds to Revelation

Revelation does not destroy reason. It builds upon it. When God reveals Himself, our proper response is faith. This is not blind submission. It is trust based on the authority of the One who speaks.

St. Thomas Aquinas explains it this way:

“Although the truths of faith surpass human reason, they do not contradict it. On the contrary, faith perfects reason.”

God reveals what we could not discover on our own. And by doing so, He frees us from both ignorance and pride. We are no longer left to guess, but we are also reminded that we are not the measure of all things.

Why Would God Choose to Reveal Anything?

God does not reveal Himself because He must, but because He loves. He wants to be known, not just as a Creator, but as a Father. His revelation is not a list of abstract ideas. It is a story. It is a relationship. It is an invitation.

Without revelation, we might strive for God out of fear or confusion. With revelation, we seek Him as sons and daughters.

This also means that revelation is personal. It is not information for information’s sake. It is meant to shape us, not just educate us.

As St. Gregory the Great put it,

“The sacred page is a letter from Almighty God to His creature.”

What We Cannot Know and Why That’s a Good Thing

There are limits to what we can know, even with revelation. We cannot comprehend God’s essence. We cannot explain the inner workings of every mystery. There is always more beyond what we grasp.

This is not a flaw. It is fitting. We are finite. God is infinite. A God we could fully explain would be a god of our own making.

In the Catholic tradition, mystery is not an excuse to avoid thinking. It is an invitation to humility and wonder. It is a call to worship.

As the mystics often say, the closer we come to God, the more we realize how little we truly understand. And that is not discouraging. It is beautiful.

Two Ways of Knowing, One God to Know

To summarize:

• Reason helps us know about God.

• Faith helps us know God.

• Natural theology tells us that there is a Creator.

• Revealed theology tells us that the Creator is Love.

Together, they give us a fuller picture. Reason sets the foundation. Revelation builds the house. Faith opens the door.

Coming Next: Why Religion Matters

In Part 6, we’ll explore the meaning of religion itself. What is it? Can it be defined? Why are people so drawn to it—or so passionate against it? Is it just a human invention, or is it part of what we are made for?

Stay with me.