Corrupt character and vile deeds are the manifestation of irreverence and disregard for God here.
While it might be clever and make a great t-shirt slogan to declare April 1 to be "National Atheist's Day," it is not theologically accurate. Worse, it sucks the prophetic power out of a statement that was intended as a warning to those of us who know that there is a God and that God is to be revered.
Proverbs 1:7 The fear of the Lord is the beginning of knowledge, but fools despise wisdom and instruction.
Proverbs 1:32 For the waywardness of the simple will kill them, and the complacency of fools will destroy them;
Proverbs 3:35 The wise inherit honor, but fools get only shame.
Proverbs 10:8 The wise in heart accept commands, but a chattering fool comes to ruin.
Proverbs 10:14 The wise store up knowledge, but the mouth of a fool invites ruin.
Proverbs 10:21 The lips of the righteous nourish many, but fools die for lack of sense.
Proverbs 11:29 Whoever brings ruin on their family will inherit only wind, and the fool will be servant to the wise.
Proverbs 12:15 The way of fools seems right to them, but the wise listen to advice.
Proverbs 12:16 Fools show their annoyance at once, but the prudent overlook an insult.
Proverbs 12:23 The prudent keep their knowledge to themselves, but a fool’s heart blurts out folly.
Proverbs 13:16 All who are prudent act with knowledge, but fools expose their folly.
Proverbs 13:19 A longing fulfilled is sweet to the soul, but fools detest turning from evil.
Proverbs 13:20 Walk with the wise and become wise, for a companion of fools suffers harm.
Proverbs 14:1 The wise woman builds her house, but with her own hands the foolish one tears hers down.
Proverbs 14:3 A fool’s mouth lashes out with pride, but the lips of the wise protect them.
Proverbs 14:7 Stay away from a fool, for you will not find knowledge on their lips.
Proverbs 14:8 The wisdom of the prudent is to give thought to their ways, but the folly of fools is deception.
Proverbs 14:9 Fools mock at making amends for sin, but goodwill is found among the upright.
Proverbs 14:16 The wise fear the Lord and shun evil, but a fool is hotheaded and yet feels secure.
Proverbs 14:17 A quick-tempered person does foolish things, and the one who devises evil schemes is hated.
Proverbs 14:24 The wealth of the wise is their crown, but the folly of fools yields folly.
Proverbs 14:33 Wisdom reposes in the heart of the discerning and even among fools she lets herself be known.
Proverbs 15:2 The tongue of the wise adorns knowledge, but the mouth of the fool gushes folly.
Proverbs 15:7 The lips of the wise spread knowledge, but the hearts of fools are not upright.
Proverbs 15:14 The discerning heart seeks knowledge, but the mouth of a fool feeds on folly.
Proverbs 16:22 Prudence is a fountain of life to the prudent, but folly brings punishment to fools.
Proverbs 17:16 Why should fools have money in hand to buy wisdom, when they are not able to understand it?
Proverbs 17:24 A discerning person keeps wisdom in view, but a fool’s eyes wander to the ends of the earth.
Proverbs 17:25 A foolish son brings grief to his father and bitterness to the mother who bore him.
Proverbs 17:28 Even fools are thought wise if they keep silent, and discerning if they hold their tongues.
Proverbs 18:2 Fools find no pleasure in understanding but delight in airing their own opinions.
Proverbs 18:6 The lips of fools bring them strife, and their mouths invite a beating.
Proverbs 18:7 The mouths of fools are their undoing, and their lips are a snare to their very lives.
Proverbs 19:1 Better the poor whose walk is blameless than a fool whose lips are perverse.
Proverbs 21:20 The wise store up choice food and olive oil, but fools gulp theirs down.
Proverbs 23:9 Do not speak to fools, for they will scorn your prudent words.
Proverbs 26:6 Sending a message by the hands of a fool is like cutting off one’s feet or drinking poison.
Proverbs 26:9 Like a thornbush in a drunkard’s hand is a proverb in the mouth of a fool.
Proverbs 26:11 As a dog returns to its vomit, so fools repeat their folly.
A final observation is that Paul turns the tables on all of this and let's some early believers know that to follow Jesus is to risk being called a fool. The Romans even called the Christians "atheists" because they did not participate in the worship of the multiple gods of the empire. Paul affirms the simple and obedient faith of the people of the Way as being at odds with the world's power structures and thought patterns, warning them that they will appear foolish and stick out like sore thumbs: