Cleansing by fire is a way to make a new man, just as being poured in a crucible and refined. This is the goal of Purgatory.
Zechariah 13:9 And I will put this third into the fire, and refine them as one refines silver, and test them as gold is tested. They will call upon my name, and I will answer them. I will say, ‘They are my people’; and they will say, ‘The Lord is my God.’”
1 Peter 1:7 So that the tested genuineness of your faith—more precious than gold that perishes though it is tested by fire—may be found to result in praise and glory and honor at the revelation of Jesus Christ
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1 Peter 4:12 Beloved, do not be surprised at the fiery trial when it comes upon you to test you, as though something strange were happening to you.
1 Peter 1:6-7 In this you rejoice, though now for a little while, if necessary, you have been grieved by various trials, so that the tested genuineness of your faith—more precious than gold that perishes though it is tested by fire—may be found to result in praise and glory and honor at the revelation of Jesus Christ.