The Bible says that God has revealed Himself to humanity in four different ways. They include (1) Nature (2) Our conscience (3) Jesus Christ (4) The Bible.

1. Nature Has Revealed God

The universe with its vastness and complexity gives testimony to God and His glory. The Bible says:

When I consider your heavens, the work of your fingers, the moon and the stars, which you have ordained, what is man that you are mindful of him (Psalm 8:3,4).

Yet the testimony of nature only tells us about God in a limited way. The Book of Job states this fact.

He binds up the water in his thick clouds, yet the clouds are not broken under it. He covers the face of his throne, and spreads his cloud over it . . . Indeed these are the mere edges of his ways, and how small a whisper we hear of him! But the thunder of his power who can understand (Job 26:8,9,14).

There Is No Excuse For Anyone

But that which we can know about God leaves us without any excuses.

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 1:20).    

Therefore the Bible says that God has revealed Himself through nature.                 

2. Our Conscience Tells Us That God Exists

God has also revealed Himself through the spirit, or mind, of humanity. All societies have a certain moral code built into them in which stealing, lying, murder, and such are universally condemned. Humanity’s sense of right and wrong testifies to God’s existence. The Apostle Paul wrote:

For when Gentiles, who do not have the law, by nature do the things contained in the law, these although not having the law are a law to themselves, who show the work of the law written in their hearts, their conscience also bearing witness, and between themselves their thoughts accusing or else excusing them (Romans 2:14,15).

3. Jesus Christ Has Revealed God

God has also revealed Himself to the world through the person of Jesus Christ.

God, who at various times and in different ways spoke in time past to the fathers by the prophets, has in these last days spoken to us by his Son, whom He has appointed heir of all things, through whom also he made the worlds (Hebrews 1:1,2).

Jesus Himself testified that He had come to earth to reveal the will of God the Father.

All things have been delivered to me by my Father, and no one knows the Son except the Father. Nor does anyone know the Father except the Son, and he to whom the Son wills to reveal him (Matthew 11:27).

4. The Scriptures Testify Of God’s Existence

God also has revealed Himself through the written Word, the Scriptures. The Bible is God’s revelation of Himself to humankind. The Scripture says of itself:

All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof for correction, for instruction in righteousness (2 Timothy 3:16).

The Bible is humankind’s source for the knowledge of God and His plan.

God Has Given Ample Opportunity For Belief

God has given humanity ample opportunity to know about Him by means of nature, the human conscience, Jesus Christ, and through the Bible. Humanity has no excuse whatsoever for rejecting God.

Summary

God has revealed Himself to the human race in four major ways: nature, the human conscience, the Person of Jesus Christ, and finally in the Bible. Each of these methods testifies to his existence. Humanity has no excuse whatsoever for rejecting him.