What is the difference between God hiding things in Luke 18 and the gospel being hid in 2 Corinthians 4?
In Luke 18, God hid from the twelve the truth that He would be crucified and rise again, so they heard none of it. In 2 Corinthians 4, the gospel is hid to the lost, and the god of this world has blinded their minds. The first is God's hiding; the second is the gospel veiled to unbelievers.
Les teaches that Luke 18 shows God's prerogative to hide things from the human race: when Jesus told the twelve He would go to Jerusalem, be crucified, and rise the third day, the next verse says they heard none of those things because it was hid from them. That hiding was done by God. In 2 Corinthians 4, Les says we are dealing with the other side of the coin: "our gospel" is hid to them that are lost. The believer understands what the gospel is because it is what got him where he is, but the lost do not understand their plight. Verse 4 explains that in these unbelievers the god of this world has blinded the minds of them. Thus Luke 18 emphasizes God hiding truth from the twelve, while 2 Corinthians 4 emphasizes the gospel being hidden from the lost by the god of this world's blinding.
In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.