A verse to consider:

“My people are foolish; they know Me not; they are stupid children; they have no understanding. They are ‘wise’ in doing evil! But how to do good they know not.” (Jeremiah 4:22)

Note: ‘My people’ —> ‘know me not’ (the reason for foolishness & stupidity as this verse reveals).

More literally, it reads:

“For My people are foolish, Me they have not known, Foolish sons are they, yea, they are not intelligent, Wise are they to do evil, And to do good they have not known.” (Jeremiah 4:22)

P/S:

‘Evil’ chiefly stems from ‘disobeying His Word/Command’.