It's an awesome thing to think that God would remember our work for Him. The judgment of believers is for the purpose of reward. Believer's sins have been forgiven and forgotten but their works are remembered by God (Heb 6:10).

1 Cor 3:11-15

11 For no man can lay a foundation other than the one which is laid, which is Jesus Christ. 12 Now if any man builds upon the foundation with gold, silver, precious stones, wood, hay, straw, 13 each man's work will become evident; for the day will show it, because it is to be revealed with fire; and the fire itself will test the quality of each man's work. 14 If any man's work which he has built upon it remains, he shall receive a reward. 15 If any man's work is burned up, he shall suffer loss; but he himself shall be saved, yet so as through fire.
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Heb 6:10

10 For God is not unjust so as to forget your work and the love which you have shown toward His name, in having ministered and in still ministering to the saints.
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The unsaved have not placed their faith in Christ (who completed the work necessary for salvation); therefore their sin is recorded and they will be judged accordingly.


Rev 20:11-15

11 And I saw a great white throne and Him who sat upon it, from whose presence earth and heaven fled away, and no place was found for them. 12 And I saw the dead, the great and the small, standing before the throne, and books were opened; and another book was opened, which is the book of life; and the dead were judged from the things which were written in the books, according to their deeds. 13 And the sea gave up the dead which were in it, and death and Hades gave up the dead which were in them; and they were judged, every one of them according to their deeds.14 And death and Hades were thrown into the lake of fire. This is the second death, the lake of fire. 15 And if anyone's name was not found written in the book of life, he was thrown into the lake of fire.
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