"Delusion" is the misunderstood, falsely interpreted literal and spiritually-shaped sayings of the Prophets, Jesus Christ and the Apostles, a perverted understanding and fulfillment of God's Will and His Commandments.
"Delusion" is man's worldview that does not correspond to the Divine Truth, his erroneous representation of the reality around him.
"Delusion" is false religious and other doctrines and priorities, leading man to a dead-end, spiritually lifeless state.
"Ignorance" is also a morally, spiritually distorted way of life, which does not lead a person to the true purpose and meaning of life, indicated to him by the Creator in His Covenants, the Commandments.