In Job’s day, everyone knew that God was rewarding good behavior with things like wealth and good health (Job 1:1-3). That’s why Job’s three friends all told him, in so many words, that he must have sinned to have incurred the loss of his health and wealth. This is also how God dealt with the people of Israel under the law (Lev. 26; Deut. 28). In such cases, God would use Satan and his host to effect the punishment (1 Kings 22:22; 1 Chron. 21:1), as well as the natural wickedness of men (Isa. 10:5-7).
But we are not under that kind of conditional blessing because we are not under the law, we are under grace (Rom. 6:14,15). Today God blesses us up front with “all spiritual blessings” in Christ (Eph. 1:3), and then beseeches us to walk worthy of them (Eph. 4:1; Col. 1:10). That means that pandemics and natural disasters are not Satan’s doing, they are just the result of living in a creation that is cursed by sin (Rom. 8:22, 23). Today Satan is “an angel of light” (2 Cor. 11:14), and his devils are “ministers of righteousness” (2 Cor. 11:15). They are busy teaching “doctrines of devils” (1 Tim. 4:1), not wreaking havoc in the material world.