The announcement by John in Rev 7:4-8 of the number of those who are sealed marks the completion of the sealing. John hears that their number is 144,000 from the 12 tribes of Israel.
The reference here is not to a literal number but to what it signifies. The number 144,000 consists of 12 times 12 times 1,000. Twelve is a symbol of God’s people: the tribes of Israel and the church built upon the foundation of the Twelve Apostles (Eph. 2:20). 1,000 was the basic military division in the camp of Israel (Num 31:4-5)…also the result of 10*10*10, a perfect cube, symbolizing completeness.
Thus, the number 144,000 stands for the totality of God’s end-time people: “All Israel” (Jews and Gentiles) who are ready for Christ’s return and who will be translated without seeing death (Rom. 11:26, 1 Cor. 15:51-53).
The 12 tribes listed in Revelation 7 are, obviously, not literal, because the 12 tribes of Israel, encompassing both the Northern and Southern Kingdoms, are not in existence today. The 10 tribes of the Northern Kingdom were taken into captivity during the Assyrian conquest (2 Kings 17:6-23), where they became integrated with other nations. Thus, the 12 tribes do not constitute Judaism today.
Also, the list of the 12 tribes in Revelation 7 is like no other found in Scripture (compare Num. 1:5-15, Ezek. 48:1-29). Judah is listed as the first tribe (Rev. 7:5) instead of Reuben (compare with Num. 1:15). Also, the tribes of Dan and Ephraim, included in the lists of Numbers 1 and Ezekiel 48, are omitted from the list in Revelation 7, while Levi and Joseph are included instead (Rev. 7:7, 8). The obvious reason for the exclusion of Ephraim, and apparently Dan, from the list in Revelation 7 is that in the Old Testament these two tribes are apostate and idolatrous (1 Kings 12:29, 30; Hos. 4:17).
The list of the tribes in Revelation 7 is not historical but spiritual. The absence of Dan and Ephraim from the list suggests that the unfaithfulness of these two tribes will have no place among God’s sealed people. Also, the church in the New Testament is referred to as the 12 tribes of Israel (James 1:1).
The 12 tribes in Revelation 7 stand for the entire people of God who endure to the end, both Jews and Gentiles. In other words, it’s not that literal Israel as a country today is what John is referring to but to spiritual Israel i.e. anyone who truly believes in God (Rom 11:11-32) but more importantly, endures to the very end.💡🙌🏾
Source reference: SDA 1Q19 Quarterly