The vision of the 144,000 opens with a reference to heavenly control of the elements. We perhaps do not see the significance of this, but John’s readers would have. In the ancient world, the elements were regarded by pagans as being ruled by different false gods. John here says the elements are under the control of the only God.
The four angels are depicted as being ready to unleash storms on the earth, which is similar to what happened with the seals. It is very likely that the four angels function in a similar way to the four horsemen of chapter 6. Before they do begin to destroy, another angel appears and commands them not to do so until the servants of God have been sealed. Then we are told that the number to be sealed was 144,000, made up of 12,000 from each of the tribes of Israel.
Who are the 144,000? Personally, I think the vision refers to the same people as in the next vision, the great crowd, but looked at from different viewpoints. The first vision, the 144,000, describes God’s people during the time of God’s judgments on those who rebel against him and the second vision, the great crowd, describes them after the time of judgment is over. The point of the vision of the 144,000 is to show that the people of God are safe despite what is happening throughout history. The 144,000 are mentioned again in Revelation 14. In Revelation 14 they have arrived in heaven, which is another reminder that they reached heaven safely.
John tells us that the sealing process of the 144,000 began before the troubles commenced (7:3). The seal was the mark of ownership, whereby God intimated that the sealed people were his. Believers belong to God in a variety of ways: by creation, by choice and by salvation. They were sealed in order that they would not be harmed by God’s judgements, although some of them would be harmed by human opposition.
It is important to note that they are numbered as an army. This list of twelve tribes of Israel obviously has an Old Testament allusion and those readers who were familiar with the Old Testament would see the point. During the history of Old Testament Israel it was common for each tribe to provide soldiers for a military campaign. John here is reminding his readers that they are involved in a battle against God’s enemies. To each of them came their call-up papers, which is the gospel invitation asking them to leave the army of the enemy and come and join the army of the King. They serve under a Commander who knows how to win the war, who has provided most of the victory already, and who will make each of them more than conquerors. They will receive a great reward for serving in his army.