For My people are foolish. They do not know Me. They are stupid children, and they have no understanding. They are wise to do evil, but they do not know to do good.
And He said, To you it has been given to know the mysteries of the kingdom of God, but to the rest in parables, that seeing they might not see, and hearing, they might not understand. Isa. 6:9
But a natural man does not receive the things of the Spirit of God, for they are foolishness to him, and he is not able to know them, because they are spiritually discerned.
having been darkened in the intellect, being alienated from the life of God through the ignorance which is in them because of the hardness of their heart,
But the one hating his brother is in the darkness, and walks in the darkness, and does not know where he is going, because the darkness blinded his eyes.