Who are 'the wise' in 1 Corinthians 3:20 whose thoughts are called vain?
In 1 Corinthians 3:20, 'the wise' are the wise of this world—those whose human wisdom and thoughts God calls vain. Their craftiness is caught by the Lord, and their reasoning amounts to nothing in God's sight, being foolishness to Him.
Les explains that 1 Corinthians 3:20 cites the principle that God takes the wise in their own craftiness, which he thinks comes from Job. The next phrase identifies 'the wise' as the wise of this world, whose thoughts the Lord knows and calls vain. Les connects this with Psalm 94:11, where the Lord knows the thoughts of man and they are vanity. He stresses that all Scripture fits together, God knows every thought, and in the final analysis human thoughts go up in a puff of smoke and amount to nothing.
And again, The Lord knoweth the thoughts of the wise, that they are vain.