Corrosion pot

Ezekiel 24:1-14
A parable said about city of Jerusalem when the king of Babylon has laid siege to Jerusalem
The Lord asked Ezekiel used a pot whose corrosion is in it, put in pieces of meat. Heap on the logs, kindle the fire, boil the meat well, mix in the spices, and let the bones be burned up. Then set it empty upon the coal, that its uncleanness may be melted in it, its corrosion consume.
On account of your unclean lewdness, because I would have cleansed you and you were not cleanse from your uncleanness, you shell not be cleaned anymore till I have satisfied my fury upon you.
corrosion腐蝕:  the act or process of corroding; condition of being corroded.
Why?
The has given them opportunity to repent and make them clean, but they refused, so the judgement comes upon them, Jerusalem will like a pot be burned up. 
The corrosion is the lewdness of Jerusalem, it is unclean.
The Lord treated them with mercy but they reject the words of God, God's judgement came, the Lord is righteousness forever.
The process of corroding take a while, it is like our life's faith to the Lord getting weak. It is take time, if we won't care, the corrosion be shown up.
How?
Deal Lord, please help me be ware about my deed and mind, don't getting corroding, blesses me shine and clean before you.