My Friend Rev. Davis Matovu wrote this brief summary on chapter 6: The imagery in this chapter is adapted from the angelic horsemen sent by God to patrol the earth in Zechariah 1:8-11 and 6:1-8, though used in a different way. Some scholars suggest that the horsemen portray angels of judgment, others symbols for Christ coming in judgments, and still others simply symbols for judgments in general. Although divine judgments in history are a major OT theme, pagans also recognized and would have understood John’s point; most cultures in history have recognized the existence of divine judgments. Jewish apocalyptic traditions associated some of these judgments, such as war and famine, with the time just preceding the end of the age; cf. Matt 24:6-8.
Since the casting down of Satan to earth, God’s creation and His people have been targets of Satan’s attacks, and this situation will continue until the second coming of Christ. It is also important to note that writers of apocalypses move backward and forward in human history, and so the disasters recorded in Revelation (seals, trumpets and bowls) should not be squeezed into an artificial chronology. Revelation is an apocalypse and must be read, studied and interpreted by the rules of that genre. Thus John’s account of the seals (and trumpets and bowls) must be read as a working out in detail of the apocalyptic idea that the second coming of Christ will be preceded by periodic historical disasters, which will affect the whole present order in one way or another.
Back to me: six seals are opened before the scene shifts: After the "four horsemen" of the apocalypse, we encounter this great scene in heaven (beginning at 9). Notice that from under the altar the souls of those who had been slaughters for the word of God are crying out "how long?" How long before before they are avenged. These are the martyrs who have died in the persecution of the church. In the first century alone this group numbered in the thousands of thousands. Notice that they are under the altar, that is in the place where the blood of the sacrifice would flow. This serves as a poignant reminder to those enduring persecution that the times of trial and suffering will come to an end: they may end with the offering of my life or they may end with the coming of Christ but they will end. This is a word of hope to a persecuted people.