In 1126 This Present Evil Age, Rev.
Catania shows us the difference between the Greek words aion and kosmos, both translated "world".
Aion is better translated "age".
The devil is the god of this present evil age.
We are warned that without the spiritual armor of God, we are in danger.
He compares it to hypoxia, lack of oxygen, that people suffer from if they are exposed to extreme heights where air pressure is too low.
It is an invisible killer.