Every man's work shall be made manifest: for the day shall declare it, because it shall be revealed by fire; and the fire shall try every man's work of what sort it is. The day shall declare it, because it shall be revealed by fire - There is much difference of opinion relative to the meaning of the terms in this and the two following verses. That the apostle refers to the approaching destruction of Jerusalem I think very probable; and when this is considered, all the terms and metaphors will appear clear and consistent.
The day is the time of punishment coming on this disobedient and rebellious people. And this day being revealed by fire, points out the extreme rigour, and totally destructive nature, of that judgment.
And the fire shall try every man's work - If the apostle refers to the Judaizing teachers and their insinuations that the law, especially circumcision, was of eternal obligation; then the day of fire - the time of vengeance, which was at hand, would sufficiently disprove such assertions; as, in the judgment of God, the whole temple service should be destroyed; and the people, who fondly presumed on their permanence and stability, should be dispossessed of their land and scattered over the face of the whole earth. The difference of the Christian and Jewish systems should then be seen: the latter should be destroyed in that fiery day, and the former prevail more than ever.