¹¹ Then I saw a great white throne and one seated on it. Earth and heaven fled from his presence, and no place was found for them. ¹² I also saw the dead, the great and the small, standing before the throne, and books were opened. Another book was opened, which is the book of life, and the dead were judged according to their works by what was written in the books. ¹³ Then the sea gave up the dead that were in it, and death and Hades gave up the dead that were in them; each one was judged according to their works. 

Revelation 20:11-13

This is a surprising passage for some, because TWICE here it is said that people are judged according to their works. Surely the just shall live by faith, right? How is that, if salvation is by grace through faith (and not by works!) that all people will be judged according to their works? It’s a great question, and before we dive too deeply into it, I’d like to point out that it isn’t just Revelation that notes this particular coming judgment.

• Psalms 62:12 “faithful love belongs to you, Lord.
  For you repay each according to his works.“
• Matthew 16:27 (straight from the mouth of Jesus) “ For the Son of Man is going to come with his angels in the glory of his Father, and then he will reward each according to what he has done.“
• 1 Peter 1:17, “ If you appeal to the Father who judges impartially according to each one’s work, you are to conduct yourselves in reverence during your time living as strangers.“
• And finally, and perhaps most completely, Romans 2:6-11 “He will repay each one according to his works: ⁷ eternal life to those who by persistence in doing good seek glory, honor, and immortality; ⁸ but wrath and anger to those who are self-seeking and disobey the truth while obeying unrighteousness. ⁹ There will be affliction and distress for every human being who does evil, first to the Jew, and also to the Greek; ¹⁰ but glory, honor, and peace for everyone who does what is good, first to the Jew, and also to the Greek. ¹¹ For there is no favoritism with God.“

Salvation is not by works (or good deeds/acts of righteousness, etc) but by faith. That said, as James tells us, there is no such thing as a real, living and saving faith that does not produce works of righteousness and obedience:

¹⁴ What good is it, my brothers and sisters, if someone claims to have faith but does not have works? Can such faith save him? ¹⁵ If a brother or sister is without clothes and lacks daily food ¹⁶ and one of you says to them, “Go in peace, stay warm, and be well fed,” but you don’t give them what the body needs, what good is it? ¹⁷ In the same way faith, if it does not have works, is dead by itself.

James 2:14-17

I believe that this dynamic is exactly what Jesus was referring to when He said:

¹⁵ “Be on your guard against false prophets who come to you in sheep’s clothing but inwardly are ravaging wolves.¹⁶ You’ll recognize them by their fruit. Are grapes gathered from thornbushes or figs from thistles?¹⁷ In the same way, every good tree produces good fruit, but a bad tree produces bad fruit.¹⁸ A good tree can’t produce bad fruit; neither can a bad tree produce good fruit.¹⁹ Every tree that doesn’t produce good fruit is cut down and thrown into the fire.²⁰ So you’ll recognize them by their fruit.

Matthew 7:15-20

Those who are truly saved will show evidence of good fruit/righteous deeds/works. And, according to Jesus, Christians will be judged based on these good deeds and rewarded accordingly. I do not think for Christians that the Great White Throne Judgment is a Heaven or Hell judgment, but it is a judgment of works/deeds, and I believe Paul is referring to this in 1 Corinthians 3, though he uses a lot of figurative language:

¹¹ For no one can lay any foundation other than what has been laid down. That foundation is Jesus Christ. ¹² If anyone builds on the foundation with gold, silver, costly stones, wood, hay, or straw, ¹³ each one’s work will become obvious. For the day will disclose it, because it will be revealed by fire; the fire will test the quality of each one’s work. ¹⁴ If anyone’s work that he has built survives, he will receive a reward. ¹⁵ If anyone’s work is burned up, he will experience loss, but he himself will be saved—but only as through fire.

1 Corinthians 3:11-15

John Piper, recognizing the interplay between faith and works here, offers a very sound explanation as to why the judgment by works does not mean salvation by works. Do notice how he contrasts answer #1 (salvation is by works and perfect obedience, the wrong answer); with answer #2 (salvation is by grace through faith and will produce works and obedience, the right answer.)

What is in question is how the judgment “according to works” here in Romans 2:6–10 fits together with that. I said that, in general, there are two possible answers to this question. One says that eternal life would be based on perfect obedience if anybody had it. But nobody does, and so the only way to eternal life is by faith in Christ. The other way says that God never promised eternal life on the basis of good deeds, but always makes good deeds the evidence of faith that unites us to God in Christ, who is the basis of eternal life….Eternal life is always based on Jesus Christ and through our faith. But since faith, by the Holy Spirit, always sanctifies or changes us into the image of Christ (one degree at a time, 2 Corinthians 3:18), there will be deeds that “accord with” this saving faith. So while eternal life will be awarded only to believers, it will be awarded “according to”—there will be an accord with—their deeds. There will be a way of life that God can put on display to demonstrate to the world that this person’s faith was real….Now, in none of these texts does it say that eternal life is earned by or merited by or based on good deeds. They simply say, in effect, that the final verdict of eternal life will accord with good deeds. They go together. And the reason they go together is not that works has replaced faith or that merit has replaced grace, but because the gospel of justification by faith is the power of God unto salvation. It is not a weak thing. The gospel does not come into a life and leave it under the dominion of sin. It comes in the power of the Holy Spirit. And where it is believed, trusted and cherished, it produces what Paul calls “the obedience of faith” (Romans 1:5; 16:26). And eternal life always accords with that.

John Piper, Sermons from John Piper (1990–1999) (Minneapolis, MN: Desiring God, 2007).