Opium for the Guilty
I recently asked a friend, "Do you believe God exists?"
"Sometimes I do. Usually I don't."
"Let me guess. You believe God when something bad happens or worries you; not when things are good."
"Yes, yes."
"Humans are so often like that. Seeking God only when there is no other option."

This friend from Japan goes on to describe his culture as composed of agonistics, atheists, and animists. And from what I know, Japan is a desperately dark place. Even from such an environment, my friend has an awareness of God. And whether we choose to accept or deny God's existence, that does not change the reality of His existence.

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 men are without excuse.
Romans 1:20

It is said that religion is the opium for the masses. However isn't atheism the opium for the guilty? What guilt? The guilt before a just and holy God. Mentioning a just and holy God right away makes most people want to stop listening. The rebellious heart bristles.

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. Although they claimed to be wise, they became fools
Romans 1:21-22

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

Humankind is guilty of sins and in the pleasure of evil, most deny God by the way they live. Too many times our thoughts are/were so twisted that we think: God -- the source of all good -- is the worst thing that can happen to us, when in fact nothing could be better. Let us not become callous, but instead turn from our own ways, seek after Him and never stop to run the good race.

"For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life. For God did not send his Son into the world to condemn the world, but to save the world through him. Whoever believes in him is not condemned, but whoever does not believe stands condemned already because he has not believed in the name of God's one and only Son. This is the verdict: Light has come into the world, but men loved darkness instead of light because their deeds were evil. Everyone who does evil hates the light, and will not come into the light for fear that his deeds will be exposed. But whoever lives by the truth comes into the light, so that it may be seen plainly that what he has done has been done through God."
John 3:16-20