Beware to those that deny Christ and His "it is finished" sacrifice which makes Christians "white as snow"
Come now, and let us reason together, Says the Lord, Though your sins are like scarlet, They shall be as white as snow--Isaiah 1:18Are you attempting to tie your "through fire" scripture quote with purgatory?
But whoever speaks against the Holy Spirit will not be forgiven in this world or the next. Jesus
This statement demonstrates, without doubt, the possibility of the forgiveness of some sins in the next world.
The passage from Corinthians fleshes out this process a bit more.