The Church of God and Shincheonji teach the importance of the 144,000 in Revelation, but as their membership has grown beyond 144,000, they have made various excuses for the 144,000. Until the early 2000s, they claimed that only 144,000 people are saved, but when their membership exceeded that number, they created a new doctrine that there is a great crowd. So is 144,000 a symbolic number? The 144,000 is not a symbolic number, it is actually the number of saints who will be saved. 

[Revelation 14:3] And they sang a new song before the throne and before the four living creatures and the elders. No one could learn the song except the 144,000 who had been redeemed from the earth. 

The Church of God and Shincheonji claim that the 144,000 saints who are saved on earth are the saints who believe in God in the last days, but this is incorrect. The 144000 is a prophecy of the saints who receive the Holy Spirit beginning with Joshua 2000 years ago until the end of the age, to which Paul testified as follows.

[Ephesians 2:20~22] built on the foundation of the apostles and prophets, with Christ Jesus himself as the chief cornerstone. In him the whole building is joined together and rises to become a holy temple in the Lord. And in him you too are being built together to become a dwelling in which God lives by his Spirit. 

Paul described the state of the saved as a temple being built. Joshua is the cornerstone of the temple, the apostles and prophets are the foundation of the temple, and the saved saints are the pillars of the temple that are built and connected to each other to complete the temple where the Holy Spirit dwells. John also describes the heavenly Jerusalem of 144,000 saints in Revelation 21. The Jerusalem in Revelation has 12 pillars and each pillar is 12000 high. This is a picture of 144,000 saints organized into 12000 tribes.

[Revelation 7:4~8] Then I heard how many people had been marked on the forehead. There were one hundred forty-four thousand, and they came from every tribe of Israel: 12,000 from Judah, 12,000 from Reuben, 12,000 from Gad, 12,000 from Asher, 12,000 from Naphtali, 12,000 from Manasseh, 12,000 from Simeon, 12,000 from Levi, 12,000 from Issachar, 12,000 from Zebulun, 12,000 from Joseph, and 12,000 from Benjamin. 

The heavenly city of Jerusalem, the bride of the Lamb, is not an actual city, but rather a symbol of the 144,000 who received the Holy Spirit of Yehoshua. Therefore, there are only 144,000 saints who will be built into the heavenly temple.  To be one of the 144,000, you must receive the Holy Spirit. The Holy Spirit is given to those who repent.

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[Isaiah 59:20~21] "The Redeemer will come to Zion, to those in Jacob who repent of their sins," declares the LORD. "As for me, this is my covenant with them," says the LORD. "My Spirit, who is on you, and my words that I have put in your mouth will not depart from your mouth, or from the mouths of your children, or from the mouths of their descendants from this time on and forever," says the LORD. 

Therefore, the 144000 are not manifested in one age, but starting with Jesus and ending at the end of time. However, the Church of God and Shincheonji are not aware of this fact, so they deceive people by claiming that 144000 saints come from their churches.