Contradiction with Isaiah 45:15
1 Corinthians 14:25 speaks of God being revealed, whereas Isaiah 45:15 describes God as a God who hides Himself.
Isaiah 45:15: Verily thou [art] a God that hidest thyself, O God of Israel, the Saviour.
Contradiction with John 1:18
1 Corinthians 14:25 mentions knowing in part, while John 1:18 asserts that no one has seen God at any time.
John 1:18: No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, he hath declared [him].
Contradiction with Romans 11:33
1 Corinthians 14:25 describes God's revelation, yet Romans 11:33 emphasizes the unsearchable and inscrutable nature of God's judgments and ways.
Romans 11:33: O the depth of the riches both of the wisdom and knowledge of God! how unsearchable [are] his judgments, and his ways past finding out!
Contradiction with Ecclesiastes 8:17
1 Corinthians 14:25 refers to God's manifest presence, whereas Ecclesiastes 8:17 states that man cannot fully comprehend God's work.
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].