Well again, not to take this too far, but none of us can undo our past. Is a deathbed conversion less "valid" than one early in life?
11 For no other foundation can anyone lay than that which is laid, which is Jesus Christ. 12 Now if anyone builds on this foundation with gold, silver, precious stones, wood, hay, straw, 13 each one's work will become clear; for the Day will declare it, because it will be revealed by fire; and the fire will test each one's work, of what sort it is. 14 If anyone's work which he has built on it endures, he will receive a reward. 15 If anyone's work is burned, he will suffer loss; but he himself will be saved, yet so as through fire.
1 Corinthians 3:11-15
Alternately, you might have in mind Jude 23, which I'll also put in context:
And on some have compassion, making a distinction; 23 but others save with fear, pulling them out of the fire, hating even the garment defiled by the flesh
Jude 22, 23
Dan