What does Revelation 9:5 mean?
Verse 3 referred to locust-like creatures having a power like that of a scorpion—an animal most infamous for its painful sting. Here, this is further explained. The torment brought by these creatures compares to that of a scorpion's sting. Scorpions sting with the end of their tail, not normally producing death, but the experience can be extremely painful and the effects can last several days. The Lord puts specific restraints on these locusts. They can torment only unbelievers, and only for a period of five months. Further, they are not allowed to kill them.The locust-like demons released from the bottomless pit are given a specific target: those not marked with the seal of God. In other words, they can only attack non-believers (Revelation 9:4).
Deuteronomy 8:15 reminds the Hebrews that the Lord led them safely through the Negev, "the great and terrifying wilderness," that housed "fiery serpents and scorpions." Just as the Lord protected His people from scorpions during their journey to the Promised Land, so He will exempt His sealed believers from the sting of scorpions in the tribulation, when the fifth angel blows his trumpet. Allegedly, scorpions are still common in the Negev, and a mountainous region that touches Palestine is called Akrabbim from the Hebrew Akrib, meaning scorpion.