Daily a new Bible text for devotion - EZBB
Revelation 9:1

THE FIFTH TRUMPET - LOCUSTS
John saw a star that fell from the sky to the earth - This star was evidently a person, because it says: "AND THE KEY TO THE PIT OF THE ABYSS WAS GIVEN TO HIM". This person may be Satan, as possibly suggested by Jesus' words in Luke 10:18:
"I SAW SATAN FALL LIKE LIGHTNING FROM HEAVEN".
THE KEY TO THE PIT OF THE ABYSS WAS GIVEN TO HIM, that is, God gave him the power to open or close its entrance.
However, the devil has no power over believers (only if the believer allows it). For example, when the seventy-two returned from their mission to the Lord Jesus, they enthusiastically told Him: "Lord, even the demons submit to us in Your name," and He replied: "I saw Satan fall like lightning from heaven".
The devil receives the key to the pit of the abyss to release the grasshoppers (verse 3) at the time determined by God. The Devil cannot go further than God allows. He receives the power to do so. Evil does not have absolute power or power of its own. Evil can only operate if God gives permission (Job 2:1-8). Pilate had no more power to put Jesus to death than that given by God (John 19:10-11). And even evil must cooperate for the good of believers (Romans 8:28).