The Lord is fair and He is just. He does all things right and well. He is also love. He also says that He recompenses a man according to his work.
Psalm 62:11,12 Once God has spoken;
Twice I have heard this:
That power belongs to God;
And lovingkindness is Yours, O Lord,
For You recompense a man according to his work.
Apart from the Lord our hearts are proud and everything we do is tainted with that pride. If we are good it may be because we want the praise of others or we want to feel good about ourselves. When we do wrong we will still think that we are not that bad because we can always find someone who has done things worse than us, at least in our own eyes. All of this is apart from the new heart that the Lord gives to us when we give our old heart to Him. He can not reform our old heart and so He gives us a new one.
Psalm 31:23 O love the Lord, all you His godly ones! The Lord preserves the faithful And fully recompenses the proud doer.
When we receive a new heart then we become godly in His eyes because now we have God in us. He came to save us and to make us into the image of Jesus Christ.
Ezekiel 36:26,27 Moreover, I will give you a new heart and put a new spirit within you; and I will remove the heart of stone from your flesh and give you a heart of flesh. I will put My Spirit within you and cause you to walk in My statutes, and you will be careful to observe My ordinances.
The evidence of a new heart is that you will want to walk in His ways and you will want to obey His Word. You will also be compensated but your compensation will come from walking in His ways and obeying Him. When you walk with Him then He leads you into good works that He has already prepared for you to do. You just have to obey Him and when you do, then you will enter into His joy and will know that you have done what He desired.
II Corinthians 5:10 For we must all appear before the judgment seat of Christ, so that each one may be recompensed for his deeds in the body, according to what he has done, whether good or bad.
We will all appear before the Lord and be recompensed for the deeds we have done to other Christians. All they good or are they bad? Have you loved as the Lord has loved you? Have you withheld good from someone when it was in your power to do it? Are you ready to see the Lord?
Galatians 6:9,10 Let us not lose heart in doing good, for in due time we will reap if we do not grow weary. So then, while we have opportunity, let us do good to all people, and especially to those who are of the household of the faith.
Instructions To A Young Life 