Based on Malachi 3:3
There was a group of women in a Bible study on the book of Malachi. As they were studying chapter three, they came across verse three, which says: "He will sit as a refiner and purifier of silver." This verse puzzled the women and they wondered what this statement meant about the character and nature of God. One of the women offered to find out about the process of refining silver and said she would get back to the group at their next Bible study.
That week this woman called up a silver smith and made an appointment to watch him at work. She didn't mention anything about the reason for her interest in silver beyond her curiosity about the process of refining silver. As she watched the silver smith, he held a piece of silver over the fire and let it heat up. He explained that in refining silver, one needed to hold the silver in the middle of the fire where the flames were hottest so it would burn away all the impurities.
The woman thought about God holding us in such a hot spot -- then she thought again about the verse, "He sits as a refiner and purifier of silver." She asked the silver smith if it was true that he had to sit there in front of the fire the whole time the silver was being refined. The man answered, "Yes," that he not only had to sit there holding the silver, but that he had to keep his eyes on the silver the entire time it was in the fire. If the silver was left even a moment too long in the flames, it would be destroyed.
The woman was silent for a moment. Then she asked the silver smith, how do you know when the silver is fully refined?
He smiled and answered, "Oh, that's easy -- when I can see my image in it."