"We are God’s fellow workers; you are God’s building. According to the grace of God which was given to me, like a wise master builder I laid a foundation, and another is building on it. But each man must be careful how he builds on it. For no man can lay a foundation other than the one which is laid, which is Jesus Christ. Now if any man builds on the foundation with gold, silver, precious stones, wood, hay, straw, each man’s work will become evident; for the day will show it because it is to be revealed with fire, and the fire itself will test the quality of each man’s work. If any man’s work which he has built on it remains, he will receive a reward. If any man’s work is burned up, he will suffer loss; but he himself will be saved, yet so as through fire." (1 Corinthians 3:10-15)
Which Works Burn?
Paul said He laid the foundation of Jesus Christ with the grace of God. People take grace to be interchangeable with the word power, thinking God's grace is God's power or allowance but the grace of God is actually God's loving-favor for us. The foundation of Jesus Christ was laid by showing that He is the perfect revelation of God's love towards mankind. So the works that build on this foundation don't picture sin vs lack of sin, they refer to how you present the character of God. If you build on Jesus by presenting the truth of His loving-favor your "works" are gold & so on. If you misrepresent the character of God your works will burn up.
Paul addresses in this chapter (v4, 21-22) people attaching themselves to Paul or Apollos. He says, "Let no one boast in men." Thus another type of works that burns up is when you displace or replace the importance of Jesus by promoting adherence to a human (leader, teacher, whatever). The context is about how people represent the character of God in what they say. We don't build on Jesus by being personally moral, we build on Him by speaking the truth of His love & who He is. We also build on Him by showing that love.
Saved Through Fire?
The idea that a Christian is "saved through fire" can bring up pictures of God punishing us because of our works. That itself is a misrepresentation of God's grace. When we see the word saved in the bible we almost always link it to salvation. But saved is a normal word that can apply to many things. So let's replace the word saved here with the alternate wording of "kept safe." "If any man’s work is burned up.. he himself will be kept safe, yet so as through fire." This doesn't picture God punishing us for our works. It pictures God's grace despite our works. First off it is the works that are tested by the fire, not the person. The bad works, the ways you've misrepresented or spread falsehood about God with good intentions, all of those works are the things that are burnt up. But the person is kept safe. The person is kept safe even though his works go up in flames. The person is completely kept safe through the flames as his bad works burn up. We are kept safe in Christ, saved, despite our bad works because of His great love for us.
God Will Destroy?
"Do you not know that you are a temple of God and that the Spirit of God dwells in you? If any man destroys the temple of God, God will destroy him, for the temple of God is holy, and that is what you are." People are easy to take this as a threat from God, as God threatening His children with punishment or destruction. In 1 Corinthians 6:19 Paul tells us to honor God with our body (temple) & avoid sexual immorality. He makes no threat that God will destroy or kill a Christian for being sexually immoral with their body. If this is saying God destroys us because we destroy ourselves He would also have to destroy Himself because "anyone who destroys the temple of God will be destroyed by God." Paul is reinforcing the fact that God will not destroy His own people by stating that He defends His people so it would be clear that the flames someone is "saved through" is not punishment. God holds nothing we His children do against us but it says here He does reward our works that revealed who He truly is to people.
My Paraphrase of 1 Corinthians 3:16-23
"Don't you know that you're God's temple & that His Spirit lives in you? Your works going up in flames doesn't mean God is going to harm you or punish you because if any man destroys the temple of God, God will destroy Him. God is not going to destroy His own temple nor will He destroy Himself. His temple is holy, you're His temple. Since you are holy your bad works cannot defile you but good works, letting people know who Jesus really is by telling them & loving them, bring good things.
Don't deceive yourself. The wisdom of this world makes God out to be a bad guy who would never love us like He did through Jesus. The so called wise are crafty in getting you to believe their views but God knows their "wisdom" is useless. So don't brag about how smart men are, not even me, Paul, because Jesus Christ is our wisdom from God & He has given us all things. All things belong to you, Paul, Apollos, & Peter, we're yours. You don't have to be ours, we can all be each other's. You don't have to put yourself under someone to get things, you already have all things. Use what you have. You have life, power over death, victory over the world, all things present & all things to come; they all belong to you and you belong to Christ; and Christ belongs to God."