Contradiction with John 1:9
John 1:9 refers to the "true Light, which lighteth every man" indicating the accessibility of light to all, contrasting with the selective belief and becoming "children of light" in John 12:36.
John 1:9: [That] was the true Light, which lighteth every man that cometh into the world.
Contradiction with Matthew 5:16
Here, individuals are encouraged to let their light shine before others, whereas John 12:36 emphasizes belief to become "children of light," which suggests a precondition.
Matthew 5:16: Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.
Contradiction with 2 Corinthians 6:14
This advises believers not to be unequally yoked with unbelievers because of light and darkness, whereas John 12:36 presents being children of light as a process still yet to be completed.
2 Corinthians 6:14: Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?
Contradiction with Ephesians 5:8
This verse states that believers already are light in the Lord, in contrast to John 12:36 which calls for belief to become children of light.
Ephesians 5:8: For ye were sometimes darkness, but now [are ye] light in the Lord: walk as children of light:
Contradiction with 1 Peter 2:9
Describes believers as a "chosen generation" and already a people of light, unlike John 12:36 that suggests transformation is necessary to become children of light.
1 Peter 2:9: But ye [are] a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light: [peculiar: or, purchased] [praises: or, virtues]