We are blessed with Christ Himself.
Scripture wants us to see ourselves as co-heirs with Christ. He has an inheritance He’s sharing, which is also called the “reward.” This is not about fairness. I understand that when you read the Gospels, they seem to present wages for faithful service. “Well done, good and faithful servant” (Mt 25:23). However, understand that in the whole Bible, there are two systems of righteousness presented and two “currencies” in those systems. One is of works, and one is of grace.
The works system, which is associated with the Law, is not of faith. He that pursues it will have to live by it.
"For as many as are of the works of the Law are under the curse: for it is written, Cursed is every One that continueth not in all things which are written in the book of the Law to do them. But that no man is justified by the Law in the sight of God, it is evident: for, The just shall live by faith. And the Law is not of faith: but, The man that doeth them shall live in them.” Gal 3:10-12
The Law promises blessing, life, and even the Kingdom.
However, your righteousness must exceed that of the Pharisees and the scribes. It must be perfect righteousness. If you break one point of the Law, you’ve broken the whole thing. The Law does not just speak to your outward behavior, but to the motives of your heart and what you spontaneously want. If you lust in your heart, you’ve committed adultery. If you hate your brother or call him a fool, you’re in danger of judgment.
When Jesus spoke of rewards to the Jews, He was speaking to a group of people who, in large measure, had been deceived into thinking the Law could justify them. They believed their flesh qualified them for an eternal inheritance, and their works qualified them for rewards. Even apart from the matter of sin, Christ is the one to whom all the promises were made, and yet they wanted the Kingdom apart from Him. This was especially true when they discovered He was the friend of sinners!
Jesus was using the Law for two purposes: to expose and take away their cloak for sin…
"If I had not come and spoken unto them, they had not had sin: but now they have no cloak for their sin." John 15:22
…and to show the rest of the people that by the “wage” system, they should only expect punishments, not rewards.
"And that servant, which knew his lord's will, and prepared not himself, neither did according to his will, shall be beaten with many stripes. But he that knew not, and did commit things worthy of stripes, shall be beaten with few stripes. For unto whomsoever much is given, of him shall be much required: and to whom men have committed much, of him they will ask the more." Lk 12:47-48
In Romans 4, Paul tells us that justification secures not only eternal salvation but also the reward. He also shows us that the reward must be of grace and not of debt. It cannot be gotten by works. Paul tells us in Romans that grace and works are mutually exclusive and cannot be mixed.
“And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then is it no more grace: otherwise work is no more work.” Rom 11:6
Read the book Here -> Rewards and Service in Grace