"For no other foundation can any one lay than that which is laid, which is Jesus Christ. Now if any one builds on the foundation with gold, silver, precious stones, wood, hay, stubble — each man’s work will become manifest; for the Day will disclose it, because it will be revealed with fire, and the fire will test what sort of work each one has done. If the work which any man has built on the foundation survives, he will receive a reward. If any man’s work is burned up, he will suffer loss, though he himself will be saved, but only as through fire".

-1 Corinthians 3:11-15

Paul is saying that God brings us into his "consuming fire" and purifies our souls. He purifies us of our imperfections (the wood, hay, & stubble) and the obedience to Christ (the gold & silver) stays.

Another Reason