I think we have to connect the power of Satan to the evils in men. Dominion over the earth was given to man; and when men's imaginations wax wicked they are inviting the demonic into the world. It affects so many things. It creates harmful bacteria and viruses to evolve. It creates earthquakes by toying with the tectonic plates. It affects the weather, causing famines and plagues. I think we can go the list given by Jesus in Luke 21 (or Matthew 24) and say the increasing evil in men is causing all those those things. God permits it because we're allowed to summon the demonic.
A great deal of evil can be erased by allowing those forces to play out. Some innocent people may die, but God knows how to save them. Their prayers are also helpful two ways: The more people pray and the more they pray, the less power Satan has. Sinners are given more chances to come to repentance.
When evil gets too bad, so bad that it threatens to completely overwhelm the good, God will intervene. Thus the evil in Noah's generation got stopped. If it had continued, evil would have triumphed completely -- no Light would have been left on the earth. We also see Sodom being wiped out -- I think because their evil was so great that Isaac wouldn't have survived -- God's plan for salvation would have been over. Similarly:
Matthew 24:22 And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened.
God in His Mercy does not allow sinners to completely destroy the world and make it a place so dark that even future generations could not be saved. Some of the "when" also depends on how evil is directed. If sinners could be content to kill each other and to offend only against themselves, God would not intervene. The situation is different when a sinner attacks a completely innocent person. The sinner has broken the Law of Free Will. As long as sinners choose to fight among themselves, they're doing what they want, they're not breaking the Law of Free Will. When they attack someone who is good and innocent, God will intervene if appealed to.
Notice how Jesus did not want to be killed secretly by the Jews. If he had to be killed, let the Romans do it. They did it. And by killing a completely innocent man, God was willing to remove the power they had. I'd say most of the demonic kingdom came tumbling down. You think the demonic is bad now? I think it was worse then. I think people then were so under the power of darkness, they couldn't come to the Light. When I read "great tribulation," I see it as hordes of demons being defeated. Oh yes, many remain, but I think Jesus got rid of the majority.
Demons seldom go after the completely innocent person -- they know if they do, they can be removed from the earth. Few openly disobey the rules but instead get humans to. But if someone has even the slightest flaw, a demon can spot it and go after it, trying to entice that person to sin.
I know my ideas are not ordinary, but let me continue. If I spot someone doing evil or even demonic, do I have the right to interfere? If someone has an unclean spirit which makes him ill, do I have the right to say, "I'm going to heal you"? I say no. That too is a violation of the Law of Free Will. You could even call it satanic. It is a trap to "resist evil" that way. Trying to boss Satan around when people have invited him into the world is asking for trouble -- people who go around thinking they have the right to bind any evil spirit they meet will probably regret it since they're a little satanic themselves. Even Jesus asked some people if they were willing to be healed. They had to agree to it first. He didn't always ask -- I think he knew they were willing when he didn't ask. When he asked, they were people sitting on the fence -- of two minds -- so he put the choice to them, "Choose this day. . . ."
Did he tell the demons who thought he might send them to the pit to go there? Why not? Well, they hadn't done anything that deserved being sent to the pit. They were in this world lawfully because people invited them. So when they asked to enter the pigs, Jesus said fine. I ask seriously if Jesus didn't bind every demon he met and sent it to the pit, why would Christians think they should try it?
Is there a demonic influence behind coronavirus? I'd say so, but it's not the real problem. The real problem is the sinfulness of men who invite the demonic into the world. I see malevolent or unfriendly spiritual forces behind weather disasters. Right now as I type, there are two hurricanes brewing in the Gulf of Mexico. We're having one of the worst hurricane seasons on record, perhaps it will wind up the worst. I don't blame the Devil for it though. I don't blame the malevolent spiritual forces. The fault lies with us -- people. We have the authority to exercise dominion and we are abusing that authority to wreck the planet -- corrupting nature itself at times. Disasters are to be expected when the level of wickedness becomes too great. I don't blame God or Satan. It's people. People need to repent. We read that the ground was cursed because of what Adam did. Do we think we too might be capable of doing things which cursed the very ground we walk on?
Did God Himself curse the ground, or did he inform Adam it was cursed? I think the latter. Blessings and curses do not both come from God. It cannot be. God was informing Adam of what he had made happen. Adam did it, not God; but the person who thinks maybe God curses could read the passage to mean God cursed the ground.
Genesis 3:17 And unto Adam he said, Because thou hast hearkened unto the voice of thy wife, and hast eaten of the tree, of which I commanded thee, saying, Thou shalt not eat of it: cursed is the ground for thy sake; in sorrow shalt thou eat of it all the days of thy life;
Both blessing and cursing can come from men's mouths; but it should not be, and I find it impossible to believe both curses and blessings come from the mouth of God.
James 3:10 Out of the same mouth proceedeth blessing and cursing. My brethren, these things ought not so to be.