Saint Catherine of Genoa

When gold has been purified up to twenty-four carats, it can no longer be consumed by any fire; not gold itself but only dross can be burnt away. Thus the divine fire works in the soul: God holds the soul in the fire until its every imperfection is burnt away and it is brought to perfection, as it were to the purity of twenty-four carats, each soul however according to its own degree. When the soul has been purified it stays wholly in God, having nothing of self in it; its being is in God who has led this cleansed soul to Himself; it can suffer no more for nothing is left in it to be burnt away; were it held in the fire when it has thus been cleansed, it would feel no pain. Rather the fire of divine love would be to it like eternal life and in no way contrary to it.

-- Saint Catherine of Genoa