Answer - Good question. If I'm reading your question correctly, you are asking why we would be "rewarded" or repaid for the "deeds" or "works" that we do in this life; and, secondly, what rewards we can expect.
I'm not sure I can find a given "list" of rewards that we may receive in Heaven anywhere in scripture, and I believe that is for a reason which I will speak to a little later.
First, let's look at what Jesus said in Matthew 16:27 - "For the Son of Man is going to come in the glory of His Father with His angels, and WILL THEN REPAY EVERY MAN ACCORDING TO HIS DEEDS." (NASB)
Take a look at the context in which Jesus was speaking these words. It is not necessarily "heavenly" rewards that Jesus is speaking of. Notice He says that He (The Son of Man) will repay (reward, recompense, give what is due) "every man." In other words, when Jesus comes back, every single persons works, deeds, and life will be examined and they will receive what is due them.
In this passage, recorded by Matthew, Jesus speaks of denying ourselves, taking up our crosses and following Him. He also speaks of losing our lives for His sake; all of which are works of faith. He contrasts these works of faith with the ideas of not denying self, not truly following Him, trying to save this life, and gaining the world yet losing our soul... all deeds associated with unbelief or lack of faith.
There will be both reward and punishment rendered depending on if the person is declared righteous by faith in Jesus or unrighteous because they denied Jesus (not accepting Jesus is the same as denying him). The evidence of their decision and position in Christ will be evidenced by their outward acts.
So, in this context, the reason we are "rewarded" for our deeds (what we did in this life) is based on the principle of "reaping what you have sown."
Jeremiah 17:10 - "I, the LORD, search the heart, I test the mind, Even to give to each man according to his ways, According to the results of his deeds." (NASB)
To really help illustrate this point, you should also carefully read through Romans 2:5-11; Revelation 2:23; and 22:12.
For the unrighteous:
Jeremiah 21:14 - "But I will punish you according to the results of your deeds," declares the LORD..." (NASB, see also Jeremiah 23:2)
Revelation 20:11-15 describes this punishment as eternity in the Lake of Fire (Hell).
For the righteous:
John 3:16 - "For God so loved the world, that He gave His only begotten Son, that whoever believes in Him shall not perish, but have eternal life." (NASB)
Revelation 21-22 describes eternity for the "righteous" in the manifest presence of God!
For more background on why we are judged and what the result of that judgment is please take a moment to read Pastor Joe's excellent answer entitled "The Judgment Seat of Christ."
It may also help to check out Pastor Joes' 5-part answer to the question "What is Salvation?"
You are absolutely correct that Salvation is not contingent on our works, but rather it is a "gift" of God's grace received by the individual through "faith" in Jesus Christ (Romans 3:24; 5:1, 9; Ephesians 2:8; and Titus 3:7 all support this foundational Christian doctrine).
Salvation is not (and cannot be!) "earned"(e.g. Romans 3:20-28; Galatians 2:16). Salvation is a gift.
However, faith is more than just "lip service" or a "one time" event. True, saving faith results in "transformation" via a new life, a new heart, and a new mind, all being transformed into the likeness of Christ by the indwelling power of the Holy Spirit.
I would agree with James that faith -- genuine living faith -- is a "lifestyle":
James 2:14-26 - "What use is it, my brethren, if someone says he has faith but he has no works? Can that faith save him? 15 If a brother or sister is without clothing and in need of daily food, 16 and one of you says to them, "Go in peace, be warmed and be filled," and yet you do not give them what is necessary for their body, what use is that? 17 Even so faith, if it has no works, is dead, being by itself. 18 ¶ But someone may well say, "You have faith and I have works; show me your faith without the works, and I will show you my faith by my works." 19 You believe that God is one. You do well; the demons also believe, and shudder. 20 But are you willing to recognize, you foolish fellow, that faith without works is useless? 21 Was not Abraham our father justified by works when he offered up Isaac his son on the altar? 22 You see that faith was working with his works, and as a result of the works, faith was perfected; 23 and the Scripture was fulfilled which says, "AND ABRAHAM BELIEVED GOD, AND IT WAS RECKONED TO HIM AS RIGHTEOUSNESS," and he was called the friend of God. 24 You see that a man is justified by works and not by faith alone. 25 In the same way, was not Rahab the harlot also justified by works when she received the messengers and sent them out by another way? 26 For just as the body without the spirit is dead, so also faith without works is dead." (NASB)
Passage after passage in the Scriptures link "faith" and "works" together. If our interest is merely in "proving" a case, we can quote the parts of these passages that affirm our belief and leave out the rest. There are plenty of denominations that still claim salvation must be earned through good works, and they use the Bible to make their case by selective quotations.
Why all this talk about faith associated with works? Because I believe that this -- these good works or deeds, these genuine acts that demonstrate our salvation by faith - is what believers will be rewarded for in heaven.
Jesus will examine all believers and reward them for what they did, how they lived, the things they said and thought, and how they served and loved Him and others while in this life!
2 Corinthians 5:9-10 - "Therefore we also have as our ambition, whether at home or absent, to be pleasing to Him. 10 For we must all appear before the judgment seat of Christ, so that each one may be recompensed [repaid, rewarded] for his deeds in the body, according to what he has done, whether good or bad." (NASB)
Note - This passage is speaking to believers!
Further supporting Scriptures (which I encourage you to read in their context) are: 1 Corinthians 3:13-15; Ephesians 6:7-8; and Colossians 3:23-24.
What rewards can believers expect?
If salvation is a gift that we receive by faith, then the greatest reward we can receive is already ours because of that faith: eternal life. Notice the contrast in John 3:36 between the present reality of union with God for the one who has faith in Jesus and the lack of hope and terrifying present reality for the one who rejects Jesus:
John 3:36 - "He who believes in the Son has eternal life; but he who does not obey the Son will not see life, but the wrath of God abides on him. (NASB)
The future reward for believers is an eternity in the presence of the Living God! That's the greatest reward! (See also 2 Timothy 4:8; James 1:12; and Revelation 2:10.)
Will there be other rewards or treasures that await us in eternity? I believe yes. I believe that Scripture gives us a glimpse or tiny peek of what awaits Jesus' faithful servants, who are willing to take up their crosses each day, deny themselves, and truly follow Him.
In the Revelation of Jesus Christ, the "uncovering" of hidden things, or "drawing aside of the curtain," Jesus gives us some ideas of what believers who lived out their faith can expect to receive:
- 2:7 - To the one who overcomes (prevails to the end): the right to eat of the tree of life in the "Paradise of God".
- 2:10-11 - To the one who is faithful until death: the crown of life. He who overcomes: no second death.
- 2:17 - To the one who overcomes: hidden manna, and a new name. Our nourishment and identity will be found solely in Christ!
- 2:25-28 - To the one who holds fast or remains true until Jesus comes: the authority to rule alongside Christ.
- 3:4-5 - To the ones who pursue righteousness: they will receive righteousness (white garment) and eternal life.
- 3:12 - To the one who overcomes: honor in heaven.
- 3:21 - The one who overcomes: they will sit with Jesus beside the throne of God.
- Revelation 21 and 22 contain many more glimpses of our reward, not the least of which include no death, no mourning, or crying, or pain!
Why aren't we told exactly what to expect as additional rewards beyond the reward of eternal life? Why are we told that we will receive "recompense" for our deeds and yet not told what that repayment will be?
For a few reasons, I believe:
- So that we will walk by faith and not sight. Not trying to obtain anything lesser than eternity in the presence of God!
- So that our acts of love and service that reflect Jesus to the world will be done for the best reason: because we long to be like Jesus and to please Him!
- And probably because knowing what we do know about God and His love for us, they are way beyond what our human minds could ever conceive or comprehend!
1 Corinthians 2:9 - but just as it is written, "THINGS WHICH EYE HAS NOT SEEN AND EAR HAS NOT HEARD, AND which HAVE NOT ENTERED THE HEART OF MAN, ALL THAT GOD HAS PREPARED FOR THOSE WHO LOVE HIM." (NASB)
I hope this helped answer your question. I know it did me good to remember that the greatest reward that could ever be received (or given!) is eternal life with God.