Jeremiah 9:7
Therefore thus saith the LORD of hosts, Behold, I will melt them, and try them; for how shall I do for the daughter of my people? Therefore thus saith the LORD of hosts, Behold, I will melt them, and try them; for how shall I do for the daughter of my people?
God Himself will melt and try His people in a testing judgment that purifies so as purely to purge away their dross and take away all their tin.
This melting and trying comes because of unfaithfulness, when they have turned from faithfulness and chosen their own way.
The warning is addressed to people in positions of trust who ignore God's principles, rely on their own judgment and persist in their own way, acting selfishly and pursuing their own ambitions instead of following God's principles.
For this reason it calls those so addressed to repentance and confession.
The purifying melting takes place as they seek to reach the highest standard, unify, come into the sanctifying circle of truth, draw together, walk humbly with God, and be subject one to another.
It continues as they cease seeking to be greatest and first, press together, heed every word of God, and avoid fault-finding and dissension.
In the same process they put off the old corrupt nature governed by deceitful lusts, are renewed in the spirit of the mind, put on the new nature created in righteousness and true holiness, become one, and seek those things which are above where Christ sits at the right hand of God.