Romans 1:28 continues the sequence: because they refused to acknowledge God (as in verse 21), God gave them over to depraved minds.

Romans 1:19 provides the basis: God made himself plain to them, so their failure to glorify him in verse 21 is willful ignorance.

Romans 1:32 shows the final stage: knowing God's judgment yet continuing in sin — the ultimate fruit of the darkened heart introduced in v21.

In Romans 1:31, the downward spiral continues: 'foolish' directly stems from the futile thinking and darkened hearts of v21.

In Romans 11:10, the same verb for darkening ('skotizō') appears as a curse on Israel's eyes, mirroring the darkened hearts of the ungodly in Romans 1:21.

Romans 15:9 shows Gentiles glorifying God for mercy—the very thing they failed to do in verse 21. A contrast between rejection and redemption.

In Romans 10:19, Paul quotes 'foolish nation' — echoing the foolishness of those who reject God, though here applied to Israel.

In Jeremiah 10:14, every man is stupid without knowledge about idols — mirroring the futile thinking and darkened understanding in Romans 1:21.

Genesis 8:21 says the intention of man's heart is evil from youth — echoing the darkened hearts of Romans 1:21.

Jeremiah 10:15 calls idols worthless, a work of delusion — directly connects to the futility and folly of those who reject God in Romans 1:21.

Hosea 2:8 shows Israel failing to acknowledge God as giver of blessings, using them for Baal — parallel to the ingratitude in Romans 1:21.

Habakkuk 1:16 depicts sacrificing to a net — a clear example of idolatry instead of thanking God, matching Romans 1:21.

In Luke 17:15-18, only one leper returns to give thanks — exemplifying the ingratitude Paul describes in Romans 1:21.

John 3:19 parallels the same choice: people loved darkness over light, just as in verse 21 they knew God but refused to honor him.

In Acts 26:18, turning from darkness to light is the gospel solution to the darkened hearts described in Romans 1:21.

Ephesians 4:17 describes Gentiles walking in the futility of their minds — the very same phrase and concept as Romans 1:21's futile thinking.

Ephesians 4:18 says they are darkened in understanding — directly parallels the darkened foolish hearts in Romans 1:21.

2 Timothy 3:2 lists 'ungrateful' as a characteristic of the last days — same failure to give thanks as Romans 1:21.

In 1 Peter 1:18, the same Greek root 'mataios' describes the empty way of life from which believers are redeemed, echoing the futility of minds in Romans 1:21.

In 1 Peter 2:9, being called out of darkness into light is the redemption from the darkened state of Romans 1:21.

Revelation 14:7 commands giving glory to God — the opposite of the refusal to glorify him in Romans 1:21.

Revelation 15:4 declares that all nations will glorify God — reversing the ingratitude of Romans 1:21.

Genesis 6:5 describes every intention of the heart as evil — paralleling the futile thinking and darkened hearts in Romans 1:21.

Ecclesiastes 7:29 states God made man upright but they sought many schemes — directly parallels the fall from knowledge of God into futile thinking.

In Psalm 81:12, God gives the stubborn over to their own counsels — the same divine abandonment Paul describes: they knew God but were given over to futility.

Isaiah 44:9-20 mocks idol-makers as futile — this is the practical outworking of the darkened heart in Romans 1:21: they exchange God for idols.

Psalm 50:23 affirms that giving thanks honors God—the very thing they failed to do in verse 21, making their ingratitude a dishonor.

2 Kings 17:15 shows Israel rejecting God and following idols — the same pattern of ingratitude and futile thinking in Romans 1:21.

In Jeremiah 2:5, Israel went after worthless things and became worthless — exactly the same pattern of knowing God but pursuing emptiness.

Colossians 3:15 exhorts thankfulness and peace ruling hearts—directly opposite to the ungratefulness and dark hearts in Romans.

Ephesians 5:8 recalls the same darkness of heart as the former state of believers, now transformed to light—contrasting the condition described here.

James 4:17 states that knowing the good but not doing it is sin—exactly the pattern of knowing God but not honoring Him in Romans.

1 Corinthians 3:20 quotes Scripture saying the thoughts of the wise are 'futile' — the exact same word used here for futile thinking.

In Psalm 14:1, the fool's denial of God matches the futile thinking of those who knew God but did not honor Him in Romans 1:21.

Revelation 9:20 depicts people refusing to repent from idolatry, continuing the same pattern of not glorifying God described here.

In Exodus 32:4, Israel's idolatry with the golden calf illustrates the futile thinking and failure to glorify God described in Romans 1:21.

In Psalm 94:11, God knows human thoughts are vain — directly echoing the 'futile in their thinking' of Romans 1:21.

In Psalm 53:1, the fool's denial of God mirrors the futile thinking of Romans 1:21; both describe corruption.

Psalm 107:31 calls for thanksgiving to God, directly contrasting the failure to give thanks described in Romans 1:21.

Isaiah 29:14 says God will confound human wisdom, matching the futile thinking and darkened understanding in Romans 1:21.

Isaiah 44:18 describes shut eyes and hearts that cannot understand, directly paralleling the darkened hearts of Romans 1:21.

Jeremiah 10:8 says they are 'stupid and foolish' — directly echoing the futile thinking and foolish hearts described here.

Daniel 5:23 explicitly says Belshazzar did not honor God — a direct parallel to the failure to honor God as God here.

2 Thessalonians 2:11 shows God sending a strong delusion as judgment, parallel to the futile thinking resulting from not honoring God here.

Isaiah 45:20 condemns idolaters who have no knowledge, similar to the futile thinking and failure to honor God in Romans 1:21.

Jeremiah 23:16 warns against prophets who speak visions of their own minds — matching the vain imaginations and futile thinking here.

In Acts 14:15, Paul calls idols 'vain things' — directly correlating with the futile thinking of those who fail to honor God.

Ezekiel 14:5 speaks of hearts estranged through idols — a parallel to the darkened hearts and failure to honor God here.

2 Corinthians 10:5 describes 'every thought' brought captive to Christ — the very mindset that counters the futile thinking and darkened hearts here.

1 Corinthians 3:19 declares worldly wisdom is folly to God — directly aligning with the futile thinking of those who reject God's glory.

In Psalm 10:4, the wicked's proud refusal to seek God echoes the ingratitude and lack of honor in Romans 1:21.

Hosea 7:15 says Israel devises evil against God despite his training — mirroring the ingratitude and futile thinking here.

Jeremiah 10:3-8 describes the futile customs of idolatry — a concrete example of the foolish hearts darkened in Romans 1:21.

Jeremiah 9:14 describes Israel walking after the stubbornness of their own hearts — a parallel to the futile thinking and darkened hearts here.

In Deuteronomy 29:19, the stubborn heart that presumes safety parallels the darkened, futile heart in Romans 1:21.

In 1 Samuel 2:12, Eli's sons did not know the Lord, while Romans 1:21 describes those who knew God but did not honor Him—both depict a defective relationship.

In 1 Kings 16:26, walking in Jeroboam's sin of provoking God with vanities mirrors the idolatrous futility Paul describes.

In 1 Kings 16:13, provoking God with 'vanities' illustrates the same futile idolatry as the darkened hearts in Romans 1:21.

In Jeremiah 16:19, the nations confess their fathers inherited worthless lies — same verdict on the futility of idolatry that results from not honoring God.

Colossians 2:8 warns against empty deceit and human tradition, echoing the futile thinking and darkened hearts described here.

In Job 31:27, being secretly enticed to idolatry parallels the failure to honor God and darkened hearts in Romans 1:21.

Jeremiah 4:14 calls for washing the heart from evil thoughts, relating to the darkened hearts of Romans 1:21 as a call to repentance.

Luke 17:17 shows Jesus lamenting the lack of gratitude in the nine lepers — echoing the ingratitude toward God described here.