Of the building materials listed in 1 Corinthians 3:12, only gold, silver, and precious stones can withstand fire. In the same way, only certain ways of serving God and his church will stand God’s test on the day of judgment. Paul specifically has in mind the service that is performed by preachers of the gospel (1 Corinthians 3:9–10), although it is possible to apply the image more broadly to any work of ministry.
Paul does not explain what good work (done by a preacher) looks like, nor does he explain what poor work looks like. To build with wood, hay, and straw clearly does not mean to preach false gospels and heresies. Even the preacher who has built poorly has still built on the foundation
(Jesus Christ). His life will be saved, even though his work will be destroyed (1 Corinthians 3:15).
What is clear is that there is a way of preaching and teaching that has eternal value, and a way of preaching and teaching that is of little value for eternity. The broader context suggests that Paul has in mind preaching and teaching that are focused on the gospel and the edification of believers, over against preaching and teaching that lay too much emphasis on secondary matters.
14 If the work that anyone has built on the foundation survives, he will receive a reward.