Why is the seventh seal not covered in Revelation 6?
The seventh seal is not covered in Revelation 6 because it is reserved for later treatment. Revelation 6 ends with the sixth seal, while the seventh seal introduces the trumpet judgments that follow after the midpoint. So the chapter focuses on the first six seals.
Les explains that Revelation 6 is where the seals on the scroll from Revelation 5 are being opened. That scroll was indicative of a mortgage, and the seals act as triggering mechanisms for events in time. The chapter reviews the white horse as the coming of the Antichrist, the red horse as the Russian invasion, the pale horse as famine and disease, and the black horse as the great death and destruction resulting from famine. Then at verse 12 the sixth seal is opened. Les notes there are seven seals, but the seventh will be covered later because it introduces the other trumpet judgments that follow after the midpoint.
And I beheld when he had opened the sixth seal, and, lo, there was a great earthquake; and the sun became black as sackcloth of hair, and the moon became as blood;