Why does the pale horse come after the black horse in Revelation?
The pale horse comes after the black horse because the famine symbolized by the black horse causes death and hell to follow, with power to kill a fourth of the world by sword and other means. This sequence shows the escalating judgments of the tribulation, the beginning of travail.
Les explains that the black horse symbolizes famine and a drop in the food supply. As a result of that famine and the demise of two great power structures, the pale horse appears. On this horse is Death, and Hell follows with him, and power is given to kill with the sword and other means over one-fourth of the world, whether one-fourth of geographical area or population. This is tribulation, just the beginning. In Matthew 24, after the four horsemen, Jesus says there will be famine, pestilence, and earthquakes, and all these are the beginning of travail or sorrow. The scroll in Revelation 5 pictures a paying off of a mortgage and the delivery of the earth from the curse instituted at the garden.