Contradiction with Proverbs 25:2
It is the glory of God to conceal a thing, contradicting the notion of openness in Acts 26:26.
Proverbs 25:2: [It is] the glory of God to conceal a thing: but the honour of kings [is] to search out a matter.
Contradiction with Isaiah 45:15
Verily thou art a God that hidest thyself, contrasting with Acts 26:26's assertion of things not being hidden.
Isaiah 45:15: Verily thou [art] a God that hidest thyself, O God of Israel, the Saviour.
Contradiction with Mark 4:11
Unto them that are without, all these things are done in parables, contradicting the assertion of openness in Acts 26:26.
Mark 4:11: And he said unto them, Unto you it is given to know the mystery of the kingdom of God: but unto them that are without, all [these] things are done in parables:
Contradiction with John 16:25
I shall no more speak unto you in proverbs, but I shall shew you plainly, indicating previous concealment, unlike Acts 26:26.
John 16:25: These things have I spoken unto you in proverbs: but the time cometh, when I shall no more speak unto you in proverbs, but I shall shew you plainly of the Father. [proverbs: or, parables]
Contradiction with 1 Corinthians 2:7
But we speak the wisdom of God in a mystery, hidden wisdom, which contradicts the exposure of truth mentioned in Acts 26:26.
1 Corinthians 2:7: But we speak the wisdom of God in a mystery, [even] the hidden [wisdom], which God ordained before the world unto our glory: