What is the difference between the “Great Tribulation” and “Armageddon” and what happens during them?
This is part of what is sometimes termed our “Lord’s Great Prophecy.” In this place, Jesus draws upon Daniel 12:1, which says: “At that time shall Michael stand up, the great prince which standeth for the children of thy people: and there shall be a time of trouble, such as never was since there was a nation even to that same time.”
Michael is the name applied to Jesus in his pre-human experience. Therefore this is a prophecy about the closing period of the present time period, or Gospel Age, when Jesus takes authority, to bring down old institutions, and works toward the establishment of his Millennial kingdom. The expression “stand up” is one used half a dozen times in Daniel 11 to describe a king coming to the throne. Thus Daniel 12:1 describes the time when Christ begins to exercise royal authority, as he is doing presently.
The time of trouble, of a magnitude greater than any time before, began with World War I, continued with World War II, and will end with Armageddon. Thus Armageddon brings the conclusion of the time of trouble that Jesus referred to in Matthew 24.
The word Armageddon comes from Revelation 16:16. In that chapter there are seven last plagues, which span the harvest, or ending period of the Gospel Age. In the sixth plague, forces are gathered to “the battle of the great day,” termed “Armageddon” (Revelation 16:14,16). Thus Armageddon is the closing portion of the longer time of trouble.
The gathering of nations referred to is a gathering to Israel. If you read Joel chapter three, you will find this gathering of nations to Israel described at greater length.
“Let the heathen be wakened, and come up to the valley of Jehoshaphat: for there will I sit to judge all the heathen round about” (verse 12). “The LORD also shall roar out of Zion, and utter his voice from Jerusalem; and the heavens and the earth shall shake: but the LORD will be the hope of his people, and the strength of the children of Israel” (verse 16).
You will find the same experience described also at length in Ezekiel 38, where a gathering of nations descends against Israel, God intervenes to deliver Israel, and thereafter the Millennial kingdom of Christ will bless not only Israel, but through them, “all the families of the earth.”
So, in brief – Armageddon is the closing episode of the broader “time of trouble such as never was” (Daniel 12:1). That broader “time of trouble” is also termed the “great tribulation” (Matthew 24:21).