AIR
Hebrew is a very concrete and not very abstract language; Thus, to designate what in modern language is called atmosphere, the Jews used the expression “under the sky”, thereby indicating what appeared to their eyes, that is, the void that mediates between the earth and the firmament.
This region is populated by the birds of the air (Mk. 4:32; Dan. 4:918). The Greeks and Romans also had this same opinion about the space that surrounds the earth, and they also believed that evil spirits lived there.
Saint Paul calls the Devil “the prince of the power of the air” (Eph. 2:2). He will also be dominated by Jesus Christ, at the end of time when he comes glorious in power and majesty (1 Thes. 4:17), and then the believers will be caught up into the air and will dominate the space previously populated by adverse forces.