1 Corinthians 3:13

each man's work shall be made manifest: for the day [the judgment day] shall declare it, because it is revealed in fire [as to its quality]; and the fire itself shall prove each man's work of what sort it is. [All of the building materials here mentioned were familiar in Corinth. The first three kinds were found in their fireproof temples--material worthy of sacred structures, and the latter three were used in their frail, combustible huts which were in no way dedicated to divinity. The argument is that Corinthian Christians should build the spiritual temple of God, the church, with as good spiritual material as the relative earthly material employed by their fathers in constructing idolatrous shrines. The church should be built of true Christians, the proper material; and not of worldly-minded hypocrites, or those who estimate the oracles of God as on a par with the philosophies of men. The day of judgment will reveal the true character of all who are in the church, as a fire reveals the character of the material in a temple structure. The Roman Catholic doctrine of purgatory is in some measure founded on this passage; but the context shows a purging of all evil men from the church as an entirety. There is no hint that the evil in the individual is purged by fire, leaving a residuum of righteousness. Our sins are not purged by fire, but by the blood of Christ, and without the shedding of blood there is no remission-- Hebrews 9:22]