What is the Great Tribulation?

Isaiah described the Great Tribulation in chapter 13:9-11. This is the beginning of God's wrath, which will result in literal darkness, and will be worldwide. Jesus said: "And there shall be signs in the sun, and in the moon, and in the stars; and upon the earth distress of nations, with perplexity; the sea and the waves roaring" (Luke 21:25). In short, the Great Tribulation means the time of grace is over. The climactic reason, however, is what the nations of the world have done with the land of Israel: "I will also gather all nations, and will bring them down into the valley of Jehoshaphat, and will plead with them there for my people and for my heritage Israel, whom they have scattered among the nations, and parted my land" (Joel 3:2). We've mentioned it before; all nations, without exception, are literally parting the land of Israel today. Why? Because they have refused the light of the world, thus their actions are works of darkness.