Contradiction with 1 Corinthians 8:2
1 John 2:20 states that believers have an anointing to know all things, but 1 Corinthians 8:2 suggests that if anyone thinks he knows anything, he knows nothing yet as he ought to know.
1 Corinthians 8:2: And if any man think that he knoweth any thing, he knoweth nothing yet as he ought to know.
Contradiction with Ecclesiastes 8:17
1 John 2:20 implies full knowledge through the anointing, whereas Ecclesiastes 8:17 emphasizes that man cannot fully comprehend all that God does.
Ecclesiastes 8:17: Then I beheld all the work of God, that a man cannot find out the work that is done under the sun: because though a man labour to seek [it] out, yet he shall not find [it]; yea further; though a wise [man] think to know [it], yet shall he not be able to find [it].
Contradiction with Proverbs 3:5
1 John 2:20 suggests believers can know all things, but Proverbs 3:5 advises not to rely on one's own understanding, implying incomplete knowledge.
Proverbs 3:5: Trust in the LORD with all thine heart; and lean not unto thine own understanding.