1 John 2:4 parallels the hypocrisy: claiming to know God without obedience mirrors claiming to be in light while hating.

1 John 2:11 directly repeats the point: whoever hates his brother is in darkness and walks blindly.

1 John 1:6 similarly condemns claiming fellowship while walking in darkness — a direct parallel to claiming light while hating.

In 1 John 3:13-17, John expands the same contrast: hating a brother is darkness, while love proves we have passed from death to life.

1 John 1:7 connects walking in the light with fellowship — 1 John 2:9 conversely shows that hating a brother means not walking in light.

1 John 3:10 explicitly states that failure to love brother reveals one is not of God — directly echoing the test in 1 John 2:9.

1 John 3:14 uses love for brothers as evidence of passing from death to life — the same test 1 John 2:9 applies using light/darkness imagery.

In 1 John 4:8, not loving means not knowing God — directly contrasting the hate described here. Both emphasize love as the test of light.

John 9:41 condemns claiming sight while remaining blind — mirroring the claim of light while hating a brother.

Romans 2:18-21 describes those who claim to be a light to the blind but fail to practice — the same hypocrisy of claiming light yet walking in darkness.

Leviticus 19:17 directly commands not to hate your brother in your heart, providing the OT basis for John's warning.

Matthew 5:22 equates anger and insults toward a brother with judgment, similarly linking internal hatred to spiritual darkness.

Romans 12:10 commands brotherly love and mutual honor — directly addressing the posture 1 John 2:9 says is necessary to be in the light.

Hebrews 13:1 commands continuing brotherly love — the very virtue whose absence 1 John 2:9 says proves one is still in darkness.

1 Corinthians 6:6 rebukes believers suing each other — a concrete example of brother against brother that 1 John 2:9 says reveals spiritual darkness.

1 Corinthians 13:1-3 teaches that without love, even great gifts are worthless, echoing that hatred nullifies any claim to being in the light.