Malachi 3:2-3

For he is like the refiner's fire, or like the fuller's lye.  He will sit refining and purifying.

When gold is first mined, it has impurities speckled throughout it.  In order to rid it of these impurities, it must be refined.  It is heated to a very high temperature until it turns to a liquid, at which time the impurities are separated from the gold.  Only after it is refined can it be used to make beautiful things. 

Our soul is like gold.  From the moment of our conception it is speckled with the impurities of sin.  But through Baptism, Reconciliation and the Eucharist, the Lord is constantly refining and purifying it of the sin and making it a beautiful thing.  Often at our death the soul is not yet fully refined and therefore needs to go through a final purgation of the sin.  This is what we call Purgatory.  Once it has been fully refined, it is welcomed into the kingdom that our Savior and King has prepared for us.

I come into this place
Burning to receive your peace
I come with my own chains
From wars I've fought for my own selfish gain
You're my God and my Father
I've accepted your Son
But my soul feels so empty now
What have I become?

Lord, come with your fire,
Burn my desires; refine me
Lord, my will has deceived me
Please come and free me
Refine me  

JENNIFER KNAPP- "Refine Me"