Dross is a substance related to the process of refining precious metals. The waste materials that are separated when metals are purified by smelting are called dross. Smelting involves the heating and melting of ores. Intense heat causes the dross to separate from the ore and rise to the top where it forms a scum and can be extracted, leaving a pure metal base. Dross can also refer to the impure base metal itself that exists before the smelting process begins.
In the Bible, dross symbolizes impurity. Dross is often used as a metaphor for a spiritual contaminant in God’s people: “Son of man, the people of Israel are the worthless slag that remains after silver is smelted. They are the dross that is left over—a useless mixture of copper, tin, iron, and lead” (Ezekiel 22:18, NLT; see also Isaiah 1:21–23; Ezekiel 24:11–13; 36:25; James 1:21).
The Bible says God judges wicked people who corrupt the whole of society and removes them like dross is removed from molten metal: “All the wicked of the earth you discard like dross; therefore I love your statutes” (Psalm 119:119; see also Proverbs 25:4; Jeremiah 6:28–30; Ezekiel 22:19–22).
Dross describes what is base or worthless. There is no dross in God’s Word: “The words of the LORD are flawless, like silver purified in a crucible, like gold refined seven times” (Psalm 12:6). The seven-fold refining of the Word speaks to Scripture’s perfection. There is nothing trivial, inferior, or worthless in God’s Word.
In a figurative sense, the Bible says God purges the impure and worthless dross from His people by a spiritual refining process of discipline, testing, and trials: “I will turn my hand against you; I will thoroughly purge away your dross and remove all your impurities. I will restore your leaders as in days of old, your rulers as at the beginning. Afterward you will be called the City of Righteousness, the Faithful City” (Isaiah 1:25–26; see also Isaiah 48:10; Psalm 66:10–12; Proverbs 17:3; 25:4; Jeremiah 9:7; Daniel 12:10; Malachi 3:2–3).
We all have spiritual dross in our lives—unhealthy and unwelcome practices and ideas that need to be removed. Believers in this world undergo a refining process that purifies our bodies and spirits (2 Corinthians 7:1) and proves the authenticity of our faith: “In all this you greatly rejoice, though now for a little while you may have had to suffer grief in all kinds of trials. These have come so that the proven genuineness of your faith—of greater worth than gold, which perishes even though refined by fire—may result in praise, glory and honor when Jesus Christ is revealed” (1 Peter 1:6–7).
When a metal refiner works with gold and silver, he repeats the smelting process over and over. Each time he raises the heat, he skims away more dross and increases the quality and purity of the refined metals. When God turns up the heat in our lives, and we experience a particularly fiery trial, we can take comfort in knowing that God’s refining fire is removing the dross in our lives for a good purpose. The Lord is refining us according to His holy will, and His goal is purity: “This third I will put into the fire; I will refine them like silver and test them like gold. They will call on my name and I will answer them; I will say, ‘They are my people,’ and they will say, ‘The LORD is our God’” (Zechariah 13:9; cf. 1 Peter 1:16).