"According to the grace of God which was given to me, as a wise master builder I have laid the foundation, and another builds on it. But let each one take heed how he builds on it. For no other foundation can anyone lay than that which is laid, which is Jesus Christ. Now if anyone builds on this foundation with gold, silver, precious stones, wood, hay, straw, each one’s work will become clear; for the Day will declare it, because it will be revealed by fire; and the fire will test each one’s work, of what sort it is. If anyone’s work which he has built on it endures, he will receive a reward. If anyone’s work is burned, he will suffer loss; but he himself will be saved, yet so as through fire." (1 Corinthians 3:10-15, emphasis added)
Paul tells his audience at Corinth that he was but a servant of God. It was His grace that worked through the apostle to bring about the conversion of people to Christianity at that city. Members of the church needed to focus their admiration on God rather than man. Paul was as an instrument being played at an orchestra. God used the apostles to grow His church. Compare the language of a master builder in verse ten to Proverbs 8:30.
The reference to "the Day" is to the Day of Judgment. Compare with 1 Thessalonians 5:2-9. In Christ, we receive deliverance from the eschatological wrath of God. The "fire" reveals the truth as to the state of our lives and doctrine while alive on this earth. If the Christian's work withstands this testing, then he will receive praise from God (v. 14). Jesus Christ is the foundation of our salvation. Our good works are to be motivated by an earnest desire to glorify Him.
God will evaluate the quality of every man's work. He will inspect both our actions and the motives behind those actions. Charity done with selfish ambitions in mind will not be accepted by Him. Paul's mentioning of gold, silver, precious stones, wood, hay, and straw corresponds to the quality of our works done in service to God. The Greek word for "through" in verse 15 is similar to that found in 1 Peter 3:20. If a person's works do not make it through this divine testing, he will be saved in spite of this "fire" or regardless of danger. The archeologist Paul T. Craddock wrote:
"...metal was smelted in small furnaces blown by bellows. The more rigorous melting smelting meant that is was now possible to melt out the waste material in the ore (known as the gangue) as a liquid slag that could be periodically tapped out of the furnace, enabling the process to continue for many hours and a considerable body of metal to build up in the bottom of the furnace. The long-term excavation and scientific study of the mines and smelters at Feinan, and also at the Timna of Israel, have greatly increased our knowledge of the development of nonferrous smelting technologies in the Bronze Age." (The Oxford Companion to Archeology, p. 461, under "Metallurgy in the Old World")
This imagery can be powerful in illustrating Paul's point about the purification and testing of one's work in Christ. Just as the furnace removes impurities from metal, the fire in Paul's metaphor represents trials and testing that reveal the true motives of one's heart. The rigorous process of melting and separating the slag from the metal can parallel the spiritual refinement and the discernment of lasting works versus perishable ones in the life of a believer. The historical and technological context of smelting furnishes the understanding of Paul's metaphor. It shows how thorough and enduring work in faith is what will ultimately stand the test of time and divine judgment, much like the purified metals that come out of the furnace.
If a man's works fail to pass through the testing of fire, then he will be saved. Whether his works make it past this trial or not, the Christian remains delivered from the sentence of eternal condemnation. Thus, claims to personal merit are silenced in either scenario. Grace shows itself even in the presence of judgment. Justification before God is not determined on the basis of good deeds. Compare this message with Romans 4:4-5, which says that justification is not an earned wage, but a free gift from God. The person whose works fail this testing will still be shown mercy, but is taking foolish risks with Him.