OK, perhaps we can clarify a few things here. The foundation is Christ and the foundation is sure. The building is the suprastructure of our understanding of the gospel, our teaching of it, and our works that result. All of these things depend upon the foundation for structural support, but even though we build on the most solid foundation, things can go awry. Notice that in 1 Corinthians 3:15, Paul says that even those whose works are burned up will be “saved, but only as through fire”. This implies again that salvation is not dependent upon our good works (the suprastructure), but upon the sure foundation of Jesus Christ.
It might be helpful to read what John Calvin wrote in his commentary on this passage:
“It is certain that Paul speaks of those who, while always retaining the foundations, mix hay with gold, stubble with silver, and wood with precious stones — that is, those who build upon Christ, but in consequence of the weakness of the flesh, admit something that is man’s, or through ignorance turn aside to some extent from the strict purity of God’s word. Such were many of the saints, Cyprian, Ambrose, Augustine, and the like. Add to these, if you choose, from those of later times, Gregory and Bernard, and others of that stamp, who, while they had it as their object to build upon Christ, did nevertheless often deviate from the right system of building. Such persons, Paul says, could be saved, but on this condition — if the Lord wiped away their ignorance, and purged them from all dross.
This is the meaning of the clause so as by fire. He means, therefore, to intimate, that he does not take away from them the hope of salvation, provided they willingly submit to the loss of their labor, and are purged by the mercy of God, as gold is refined in the furnace. Farther, although God sometimes purges his own people by afflictions, yet here by the name of fire, I understand the touchstone of the Spirit, by which the Lord corrects and removes the ignorance of his people, by which they were for a time held captive.”
västergötland, are we now on the same page?
Greg