To be made perfect in the Lord is to burn in the Refiner's Fire. Because we wish to be holy as He is holy, our impurities are forcibly extracted yet never without our consent. We choose to go into the fire to have our imperfections burned away. The attachments we form to this world during our life's journey become part of us, something like ennervated flesh, a body of death desperate to thrive despite its nature. It goes without saying that the members of such a body cannot endure the fire of purification. If your right eye causes you to stumble, gouge it out and throw it away from you (Matthew 5:29-30). It's better for you to lose one part of your body through temporary suffering than for your whole body to be thrown into hell to suffer eternally. All souls must taste death at least once, and for many the second death will cut off any hope of ascent on Jacob's Ladder. (Jesus Christ is the Jacob's Ladder between heaven and earth upon whom angels ascend and descend, as stated by Jesus himself in John 1:47-51.) The body of death, this human flesh, will devour the spirit if it can and will become its coffin unless the creature takes firm hold of the Ladder and begins to ascend.
The German Dominican monk Meister Eckhart (c. 1260-1328) was controversial and indeed heretical in his time. Some of his ideas were a little strange. To him, hell was a remedial process instead of an eternal destination (Matt. 25:46, 2 Thess. 1-9, Jude 1-7, Matt. 25:41, and many more.) Eckhart's hell matches the scriptural idea of the Refiner's Fire or what Catholics understand as Purgatory, from which all souls will eventually emerge white as snow and fit to enter the Presence of God. Eckhart produced many good teachings in his lifetime, one of which I will paraphrase here: In one of his dialogues, Eckhart evokes an image of himself holding a glowing hot coal. Does the coal burn him? Does it hurt him? No! To say such a thing would be to belittle and misrepresent the coal! So what is it that burns in hell? The religious authorities of Eckhart's day would have said: self-will, willful sin, the ego-driven will to disobey God no matter what. But again, Meister Eckhart differed with his orthodox contemporaries. What the coal really represents is Truth, the very Person of God Himself who alone is Truth. Since the hand that holds the coal is not at all like the coal, cannot do what the coal can do, nor has what the coal has as its instrinsic nature, it is untrue. It is unreal. It is a self-willed illusion, desperate to survive despite its nature. If the entire body of death becomes a smoking cinder on account of the coal, it can be converted into a luminous body of transfiguration. All molten dross, all irrelevancies, will have vanished without a trace. This new body will never be hurt by fire again.