How do we know that the 144,000 are God's elect?

The concept of the 144,000 in Revelation as a representation of God's elect is grounded in scripture that emphasizes God’s sovereign choice. In John 6:37, Jesus states, 'All that the Father gives Me shall come to Me,' asserting the idea that those who come to Christ are those whom God has selected. Ephesians 1:4-5 further clarifies that God chose His elect before the foundation of the world, illustrating that this selection is not random but part of His eternal plan.

Thus, the 144,000 symbolize the completeness of God’s chosen people, illustrating that their salvation is certain and irrevocable. This aligns with the doctrines of grace which assert that God's elect will ultimately be redeemed and brought to His glory, fulfilling the purpose for which they were chosen.