The fool says in his heart, “There is no God.”
They are corrupt, their deeds are vile;
there is no one who does good.
–Psalm 14:1 (NIV)–

¹⁸ The wrath of God is being revealed from heaven against all the godlessness and wickedness of people, who suppress the truth by their wickedness, ¹⁹ since what may be known about God is plain to them, because God has made it plain to them. ²⁰ 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 people are without excuse.
–Romans 1:18-20 (NIV)–

I had a dream that made me afraid.
As I was lying in bed, the images and visions
that passed through my mind terrified me.
–Daniel 4:5 (NIV)–

¹¹ I want you to know, brothers and sisters, that the Gospel I preached is not of human origin. ¹² I did not receive it from any man, nor was I taught it; rather, I received it by revelation from Jesus Christ.
–Galatians 1:11-12 (NIV)–

The Spirit himself testifies with our spirit 
that we are God’s children.
–Romans 8:16 (NIV)–

—

The contempt it puts upon the honour of God: for there is something of practical atheism at the bottom of all sin. The fool hath said in his heart, There is no God. We are sometimes tempted to think, “Surely there never was so much atheism and profaneness as there is in our days;” but we see the former days were no better; even in David’s time there were those who had arrived at such a height of impiety as to deny the very being of a God and the first and self-evident principles of religion. Observe, [1.] The sinner here described. He is one that saith in his heart, There is no God; he is an atheist. “There is no Elohim, no Judge or governor of the world, no providence presiding over the affairs of men.” They cannot doubt of the being of God, but will question his dominion. He says this in his heart; it is not his judgment, but his imagination. He cannot satisfy himself that there is none, but he wishes there were none, and pleases himself with the fancy that it is possible there may be none. He cannot be sure there is one, and therefore he is willing to think there is none. He dares not speak it out, lest he be confuted, and so undeceived, but he whispers it secretly in his heart, for the silencing of the clamours of his conscience and the emboldening of himself in his evil ways. [2.] The character of this sinner. He is a fool; he is simple and unwise, and this is an evidence of it; he is wicked and profane, and this is the cause of it. Note, Atheistical thoughts are very foolish wicked thoughts, and they are at the bottom of a great deal of the wickedness that is in this world. The word of God is a discerner of these thoughts, and puts a just brand on him that harbours them. Nabal is his name, and folly is with him; for he thinks against the clearest light, against his own knowledge and convictions, and the common sentiments of all the wise and sober part of mankind. No man will say, There is no God till he is so hardened in sin that it has become his interest that there should be none to call him to an account.

—MATTHEW HENRY’S COMMENTARY ON PSALM 14:1–