God has 3 Purposes for the Tribulation: (1) to judge wickedness, (2) a world-wide Soul-Harvest, (3) the Salvation of Israel. The key to Revelation 6-19 is understanding the Scroll with 7 Seals is the Title Deed of the earth. Derek explains the 7 Seals and first 6 Trumpets, and summarises the events at Mid-Tribulation.