144,000 & Multitude
towards8Revelation 7 speaks of two groups. First, 144,000 sealed people from the 12 tribes of Israel. Second, a great multitude from all the nations of the world that no one can count. These two groups actually refer to the same group, namely the Church, but from two different perspectives.
It is not unknown that the Bible describes the same thing from two different perspectives. See, for example, Daniel 2 and 7. In both chapters, the same empires are mentioned but represented by two different images. In Daniel 2, the empires are described as metals, but in Daniel 7, as beasts.
144,000
The first group, the 144,000, is meant to specifically express the election of the Church. It is calculated as 12 times 12,000. In the Bible, the number 12 symbolizes election, and the number 1,000 symbolizes completion. So, 12 times 12,000 means that the number of the elect is complete. God chose 12 sons, and they became Israel. Jesus chose 12 apostles, and they became the Church. As the apostle Paul explained in Romans 9:6-9, the Church is the true spiritual Israel.
Multitude
The second group, a great multitude from all the nations of the world that no one can count, is again the Church, but is meant to specifically express the fulfillment of the promise to Abraham. God promised that Abraham would be the father of many nations, and that they could not be counted. This was fulfilled through the Church, for there are Christians from every nation of the world. As the apostle Paul explained in Galatians 3:28-29, the Church is the true spiritual heir of Abraham.