The first two woes, which are the fifth and sixth trumpets, inflict torture on persons for five months and kill one-third of humanity through plagues of fire, smoke, and brimstone. At first glance, these judgments may seem capricious. However, a consistent moral discipline pervades Revelation. Their purpose is to move persons to repentance (9:20-21). Idolatry, materialism, murder, sorcery, immorality, and thefts are the sins the text lists. In ch. 18, John will apply this general list to the specific misdeeds of Babylon/Rome. The saints are spared these judgments, and the judgments are limited in time and number.
Although it often has been fashionable to sneer at the idea of one-third of the earth, waters, and light being destroyed, the moral relevance of Revelation is obvious to those who live with the greenhouse effect and the nuclear arms race. The very materialism John described in 9:20 may destroy God's creation.