I will refine them like silver
and test them like gold.
Being made pure and refined by God is a beautiful thing. Think of the beauty and value of pure gold and pure silver. Something pure is free from imperfections and blemishes and things to dilute or marr it.
But think of how gold is purified. It may be melted in fire many times over before it is completely free of impurities.
Now, fire. That doesn't seem so pretty. So the actually becoming pure - not so easy. It will mean testing. It will mean the heat will be on. It will mean that a lot of impurities may come to the surface to be removed.
But that's the important part - they will be removed, burned away. And what is left is pure. What is left is you, as God created you to be, without all the junk.
The fire does not destroy you. It does not burn indescriminantly. It only burns away what is not meant to be there. The process of refining is worth the end result.