Paul in the Epistle to the Ephesians tells us about spiritual death: "They are darkened in their understanding and separate from the life of God because of the ignorance that is in them due to the hardening of their hearts." Ephesians 4:18
There is an expression very similar in the book "The Banquet" of Plato: "Neither do the ignorant love wisdom or desire to become wise, for this is the harshest thing about ignorance".
What all this teaching is telling us, is that the ignorant do not seek wisdom because they do not believe they need it. Spiritual death in a human being occurs when a situation of ignorance cannot be corrected.
The spiritual gift of understanding is good reason, it is progressive and ethical thinking. People who have understanding can make ethical judgments. People obscured in their understanding, like Paul explain in Ephesians 4:18, are people who act by impulse, by passion.
"Spiritually dead" people do not believe they need spiritual goods, like eternal life and wisdom, this is so because the desires of the flesh harden the mind and the heart, and this becomes very noticeable when there is also a lack of intelligence. Jesus describes these people with a parable:
"Then he said to them, ´Watch out! Be on your guard against all kinds of greed; life does not consist in an abundance of possessions.´
And he told them this parable: ´The ground of a certain rich man yielded an abundant harvest. He thought to himself, ´What shall I do? I have no place to store my crops.´
´Then he said, ´This is what I'll do. I will tear down my barns and build bigger ones, and there I will store my surplus grain. And I'll say to myself, ´You have plenty of grain laid up for many years. Take life easy; eat, drink and be merry.´
´But God said to him, ´You fool! This very night your life will be demanded from you. Then who will get what you have prepared for yourself?´
´This is how it will be with whoever stores up things for themselves but is not rich toward God´" Luke 12:15-21.
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