Matthew 20

Salvation is the real reward.

Matthew 19, there is a discussion about what 'reward' the disciples would receive for their efforts.

27 Peter answered him, “We have left everything to follow you! What then will there be for us?”

28 Jesus said to them, “Truly I tell you, at the renewal of all things, when the Son of Man sits on his glorious throne, 
     you who have followed me will also sit on twelve thrones, judging the twelve tribes of Israel. 
29 And everyone who has left houses or brothers or sisters or father or mother or wife or children or fields for my sake 
     will receive a hundred times as much and will inherit eternal life. 
30 But many who are first will be last, and many who are last will be first.

Matthew 20
“For the kingdom of heaven is like a landowner who went out early in the morning to hire workers for his vineyard. 
2 He agreed to pay them a denarius for the day and sent them into his vineyard.
3 “About nine in the morning he went out and saw others standing in the marketplace doing nothing. 
4 He told them, ‘You also go and work in my vineyard, and I will pay you whatever is right.’ 
5 So they went. “He went out again about noon and about three in the afternoon and did the same thing. 
6 About five in the afternoon he went out and found still others standing around. He asked them, ‘
   Why have you been standing here all day long doing nothing?’
7 “‘Because no one has hired us,’ they answered. “He said to them, ‘You also go and work in my vineyard.’
8 “When evening came, the owner of the vineyard said to his foreman, ‘Call the workers and pay them their wages, 
    beginning with the last ones hired and going on to the first.’
9 “The workers who were hired about five in the afternoon came and each received a denarius. 
10 So when those came who were hired first, they expected to receive more. But each one of them also received a denarius. 
11 When they received it, they began to grumble against the landowner. 
12 ‘These who were hired last worked only one hour,’ they said, 
      ‘and you have made them equal to us who have borne the burden of the work and the heat of the day.’
3 “But he answered one of them, ‘I am not being unfair to you, friend. Didn’t you agree to work for a denarius? 
14 Take your pay and go. I want to give the one who was hired last the same as I gave you. 
15 Don’t I have the right to do what I want with my own money? Or are you envious because I am generous?’
16 “So the last will be first, and the first will be last.”

If I were asked to propose a moral to this parable, it would be that the disciples are looking for rewards for their service,
not understanding that the greatest exchange had already occurred - they had already been gifted their salvation, 
anything that follows that, is frosting on the cake.

To me, the denarius represents salvation, the work afterwards represents the response after the gift, out of gratitude.
The vineyard owner had decided beforehand that he was going to meet everyone's needs on that day, which he did.
They should have worked as a token of their appreciation.

But the first hired thought they were earning what they received.

The disciples had yet to overcome the temptation toward self-promotion.
They expected to carry the concept of 'status' into heaven.
Lucifer had that problem, refusing to humble himself before the One who created him.

Even so,  "Well done, good and faithful servant." 
is the only verbal reward I can remember reading, from Christ to any of his followers.

While the New Testament, in diverse places, talks about crowns the believers will receive,
Revelation illustrates that the 24 judges repeatedly affirm that Jesus actually deserves the crowns they are wearing.

Revelation 4:
  9 Whenever the living creatures give glory, honor and thanks to him who sits on the throne and who lives for ever and ever, 
10 the twenty-four elders fall down before him who sits on the throne and worship him who lives for ever and ever. 
      They lay their crowns before the throne and say:
11 “You are worthy, our Lord and God,  to receive glory and honor and power,
      for you created all things, and by your will they were created and have their being.”

***   ***   ***

Luke 10, when the 72 returned from preaching through the cities:

17 The seventy-two returned with joy and said, “Lord, even the demons submit to us in your name.”
18 He replied, “I saw Satan fall like lightning from heaven. 
19 I have given you authority to trample on snakes and scorpions and to overcome all the power of the enemy; nothing will harm you. 
20 However, do not rejoice that the spirits submit to you, but rejoice that your names are written in heaven.”  (bold, mine)

21 At that time Jesus, full of joy through the Holy Spirit, said, “I praise you, Father, Lord of heaven and earth, because you have hidden these things from the wise and learned, and revealed them to little children. Yes, Father, for this is what you were pleased to do.
22 “All things have been committed to me by my Father. No one knows who the Son is except the Father, 
      and no one knows who the Father is except the Son and those to whom the Son chooses to reveal him.”
23 Then he turned to his disciples and said privately, “Blessed are the eyes that see what you see. 
24 For I tell you that many prophets and kings wanted to see what you see but did not see it, and to hear what you hear but did not hear it.”

I leave you with a quote from John the Baptist, John 3:

26 They came to John and said to him, “Rabbi, that man who was with you on the other side of the Jordan—the one you testified about—
      look, he is baptizing, and everyone is going to him.
”27 To this John replied, “A person can receive only what is given them from heaven. 
28 You yourselves can testify that I said, ‘I am not the Messiah but am sent ahead of him.’ 
29 The bride belongs to the bridegroom. The friend who attends the bridegroom waits and listens for him, 
      and is full of joy when he hears the bridegroom’s voice. That joy is mine, and it is now complete. 
30 He must become greater; I must become less.”

Friends, the gift of salvation is the greater part of our treasure.
Let us work, in appreciation, so that others may also know Christ.
We should not try to justify our salvation, as though we deserve it.
Our salvation will always be a gift that we fall short of or earning.

And we can never deserve it, for if we deserved it, it wouldn't be salvation...God's merciful (unwarranted) rescuing of our souls.