How has God Manifested Himself through Nature?*
Creation, as a part of God’s general manifestation, affirms certain facts about God. Nature testifies to God’s existence. Paul wrote to the church at Rome.
What may be known of God is manifest in them for God has shown it to them. For since the creation of the world his invisible attributes are clearly seen, being understood by the things that are made, even his eternal power and Godhead, so that they are without excuse (Romans 1:19,20).

The Universe Gives Testimony To God
The vastness of the universe gives testimony to God as Creator. The psalmist wrote.
When I look at your heavens, the work of your fingers, the moon and the stars that you have established; what are human beings that you are mindful of them, mortals that you care for them (Psalm 8:3,4).

Nature Is Not Identical With God
It is important to realize that nature is not identical with God. When God manifests Himself through the physical world it means that he makes plain things about Himself that humans would not otherwise know.

There Are Two Main Passages To Consider
There are two main passages in Scripture that emphasize God’s general manifestation in creation-
Psalm 19:1-6 and Romans 1:18-21.

Psalm 19:1-6
The first six verses of Psalm 19 testify to the manifestation of God through His creation:
The heavens declare the glory of God; the skies proclaim the work of his hands. Day after day they pour forth speech; night after night they display knowledge. There is no speech or language where their voice is not heard. Their voice goes out into all the earth, their words to the ends of the world. In the heavens he has pitched a tent for the sun, which is like a bridegroom coming forth from his pavilion, like a champion rejoicing to run his course. It rises at one end of the heavens and makes its circuit to the other; nothing is hidden from its heat. (Psalm 19:1-6)

The following facts are found in these verses.

1. God’s Glory Is Being Proclaimed
The heavens are a declaration to the fact of God’s glory. It is a sign to the entire human race that God does exist.

2. The Testimony Is Constant
This manifestation about God’s power and majesty is constant, occurring “day after day” and “night after night.” Humans are constantly reminded of God’s existence.

3. This Manifestation Is Nonverbal
This manifestation about God does not consist of words- it is nonverbal revelation. The heavens, therefore, offer a silent continual testimony to God.

4. It Is Worldwide In Scope
The scope of this testimony is worldwide. All people, everywhere, have access to this form of God’s manifestation. There are no geographic barriers.

5. There Is No Language Barrier
Since this is a non-verbal form of communication there is no language barrier. All people, in every language, are able to comprehend this form of God manifesting Himself.

6. The Sun Gives Constant Testimony
The shining of the sun in the sky gives testimony to the existence and care of God. Like the sun, the existence of God is obvious to all. Nothing can hide from the sun; no one can hide from God. Facts about God are there for all to see.

Romans 1:18-21
A second passage that speaks of God’s manifestation through nature is Romans 1:18-21. Paul wrote.
The wrath of God is being revealed from heaven against all the godlessness and wickedness of humanity who suppress the truth by their wickedness, since what may be known about God is plain to them, because God has made it plain to them. For since the creation of the world God’s invisible qualities - his eternal power and divine nature - have been clearly seen, being understood from what has been made, so that humans are without excuse. For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened (Romans 1:18-21). 

The following important truths about God’s general manifestation can be learned from this passage.

1. The Testimony About God Is Clear
God has left a witness of Himself for everyone. No one has any excuse.

2. Conclusions Can Be Drawn About God And His Existence
Because of the clear testimony about God from nature, conclusions can and should be drawn about God’s existence.

3. The Testimony Is Constantly Witnessed By Everyone
As Psalm 19 affirms, this testimony is constantly being witnessed since the time God created the world.

4. General Manifestation Holds People Accountable
Because of the witness of nature, people are held accountable to God for the information that God has made plain to them.

5. This Type Of Manifestation Is Limited In What It Can Do
Manifestation from nature, or creation, is limited in what it tells us. Only certain aspects about God’s invisible qualities or nature are made plain. Specifically, “His eternal power and divine nature.”
From these two passages it is clear that everyone is aware of the existence of God through the testimony in creation.

The testimony about God’s existence from nature should lead humans to seek to discover who is the Creator.

From The Smallest To The Largest God Has Manifested Himself
Whether it be from the smallest atom or the largest galaxy, the most simple life form to the most complex, the living God has manifested himself to humankind.

All Of This Is Still Not Enough
Still, the manifestation of God in creation is not sufficient for us to know Him. The fact of creation has been corrupted by sinful humanity. Paul wrote.
Because they exchanged the truth about God for a lie and worshiped and served the creature rather than the Creator, who is blessed forever! Amen (Romans 1:25).

Humanity rejected the Creator and worshipped the creation instead.

There Is No Direct Contact With God
In addition, nature does not bring us into direct contact with God. It makes plain the power of God without revealing His person. Humanity needs more than the testimony of creation to know exactly what God is like and what He requires of us.

Nature Is Limited As A Source Of Truth
Nature can give us only a partial perception of God. From nature we can discover the wisdom and power of God. However nature is limited as a source of truth about God. Human beings are only able to infer certain things about God from nature because there are no explicit statements about him. We are not competent to understand anything more that certain general facts about God. This is due to our limitations as human beings as well as our fallen sinful nature.

Summary
The Bible testifies that “nature” or “creation” gives clear testimony to God’s existence. Everyone, everywhere, has this testimony. Natural manifestation is more than sufficient to make humanity responsible and to show them they are “without excuse.” Consequently humans should attempt to find out who this Creator is and what He requires of them. Unfortunately, many people have corrupted the manifestation of God in nature and have chosen to worship and serve the creation rather than the Creator. Instead of worshipping the Creator, they have turned creation into a god. For this, God has pronounced judgment upon them.
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* Adapted from a post by Don Stewart at
https://www.blueletterbible.org/faq/
don_stewart/don_stewart_377.cfm
with minor edits.
The primary edit is the replacement of the word “revelation” with “manifestation.” “Revelation” presumes verbal declaration, but there are no words in nature. This is an important fact because God’s manifestation in nature, unlike verbal revelation, does not require it to be in a particular language. This contrast is of extreme importance since God has revealed Himself verbally in Scripture, and the term “revelation” is appropriate only to that verbal revelation of His nature.