God’s Two Seals: The Seal of the Gospel and the Apocalyptic Seal
"To summarize, in both the seal of the gospel and the apocalyptic seal, the sealing work is done by the Holy Spirit. The first one, the seal of the gospel, is placed on all those who accept Jesus as their Savior, and it is placed at the time they accept Him (2 Cor. 1:22; Eph. 1:13; 4:30; 2 Tim. 2:19). The second one, the apocalyptic seal, is placed on those who have received the first seal and are alive and faithful to their calling during the apocalyptic days that come just before Jesus returns the second time (Rev. 7:3, 4, 14–17). The first is a seal of salvation, declaring that a person is saved by Christ and is part of God’s family, with that status remaining so long as the person remains faithful to Christ. The second is a seal of protection that guards the faithful ones during the time of persecution that comes in the apocalyptic period. One is a seal of acceptance, and the other is a seal of final confirmation. The first seal is initial declaration that a person belongs to Christ and is placed at the time that person accepts Jesus. The second confirms faithfulness in following the Lamb and God’s leadership in their lives, doing His will, keeping His commandments, and living according to His revealed Word during earth’s final hours (Rev. 7:14–17; 12:17; 13:10; 14:4, 5, 12; 17:14; 19:10). The first seal is placed at the time of acceptance of Christ as Savior, and the redeemed retain it as long as they remain faithful to their calling. The second seal is placed on those who have received the first seal and live during the apocalyptic days, faithful to their calling. Although the seal of the gospel can be broken by falling away from faith, the apocalyptic seal is permanent."
Moskala, Jiri, "God’s Two Seals: The Seal of the Gospel and the Apocalyptic Seal" (2017). Faculty Publications. 782.