Isa 5:21 How horrible it will be for those who think they are wise and consider themselves to be clever.
those who think they are wise .
They are inflated with their own ‘ego’ i.e a false opinion of themselves and their own knowledge of the situation. They are overly self-confident and vain.
Pro 3:7 Do not consider yourself wise. Fear the LORD, and turn away from evil. To be wise in your own eyes (or in your own opinion or estimation) Know-alls consider that they are cleverer than others. They are self-conceited. This was a very bad characteristic of the generation in which Isaiah lived, especially of the Jews of His day.
- It fostered PRIDE and
- It rendered them unwilling to be instructed, especially by Prophets like Isaiah.
- They thought they were wise enough and so, they would not listen to others.
a false estimate of human wisdom leads to PRIDE. True wisdom comes down from the ‘Father of Lights’