In Romans 1:21, the root of these sins is shown: they knew God but did not honor Him, leading to darkened hearts.

In Romans 1:20, Paul argues creation reveals God leaving humanity without excuse — the basis for the moral corruption listed here.

In Romans 3:11, Paul echoes 'none that understandeth' — directly parallel to the 'without understanding' in this verse.

In Jeremiah 4:22, God's people are 'foolish, without understanding, wise to do evil' — identical themes to this list.

In Isaiah 33:8, 'broken the covenant' and 'regardeth no man' directly parallel the covenant-breakers and unmerciful of Romans 1:31.

In Isaiah 27:11, 'a people of no understanding' who receive no mercy — directly matching 'without understanding' and 'unmerciful'.

Genesis 45:14 depicts Joseph's natural affection for his brother Benjamin, contrasting the 'without natural affection' in Romans.

Ezekiel 17:16 describes breaking a covenant — same word used in Romans for 'faithless' (covenant-breakers).

Isaiah 49:15 asks if a mother can forget her child, affirming natural affection and contrasting the 'without natural affection' in Romans.

Job 39:16 describes the ostrich's lack of natural affection for her young, mirroring the 'without natural affection' in Romans.

1 Kings 3:26 portrays a mother's natural affection for her child, opposing the 'without natural affection' in Romans.

2 Chronicles 16:3 parallels Asa's covenant-breaking with Ben-Hadad, illustrating the 'covenant-breakers' in Romans.

Lamentations 4:3 uses the same image of heartlessness (ostriches vs. jackals) — both describe lack of natural compassion.

Ezekiel 16:45 also condemns loathing one's own husband and children — the very 'heartlessness' listed in Romans.

1 Kings 15:19 shows Asa requesting Ben-Hadad to break a covenant, exemplifying the 'covenant-breakers' in Romans.

Ephesians 5:29 states no one hates his own flesh but nourishes it — contrasting the 'heartless' (without natural affection) in Romans.

In Proverbs 18:2, a fool delights not in understanding — mirroring the 'without understanding' trait listed here.

Hosea 10:4 condemns empty oaths and broken covenants — parallel to the covenant-breaking in Romans 1:31.

Joshua 9:20 shows Israel keeping an oath to the Gibeonites, contrasting the 'covenant-breakers' in Romans.

Genesis 21:27 shows Abraham making a covenant with Abimelech, contrasting the 'covenant-breakers' listed in Romans.