It's Not Fair

Matthew 20
1 "For the kingdom of heaven is like a master of a house who went out early in the morning to hire laborers for his vineyard. 2 After agreeing with the laborers for a denarius a day, he sent them into his vineyard. 3 And going out about the third hour he saw others standing idle in the marketplace, 4 and to them he said, 'You go into the vineyard too, and whatever is right I will give you.' 5 So they went. Going out again about the sixth hour and the ninth hour, he did the same. 6 And about the eleventh hour he went out and found others standing. And he said to them, 'Why do you stand here idle all day?' 7 They said to him, 'Because no one has hired us.' He said to them, 'You go into the vineyard too.' 8 And when evening came, the owner of the vineyard said to his foreman, 'Call the laborers and pay them their wages, beginning with the last, up to the first.' 9 And when those hired about the eleventh hour came, each of them received a denarius. 10 Now when those hired first came, they thought they would receive more, but each of them also received a denarius . 11 And on receiving it they grumbled at the master of the house, 12 saying, 'These last worked only one hour, and you have made them equal to us who have borne the burden of the day and the scorching heat.' 13 But he replied to one of them, 'Friend, I am doing you no wrong. Did you not agree with me for a denarius? 14 Take what belongs to you and go. I choose to give to this last worker as I give to you. 15 Am I not allowed to do what I choose with what belongs to me? Or do you begrudge my generosity?' 16 So the last will be first, and the first last."

Many times we see this passage talking about folks that accepted Jesus late in life as opposed to those that have spent a good bit of their lives following the Lord.
So, it comes down that the ones following the Lord for the longer time don't find it fair because the "newer" Christians got to enjoy life longer before they had to submit to rules and regulations.

There is a flaw in that thinking though - its as though the thought is that the world has more to offer for the here and now than Jesus does. It also takes grace out of the picture.
Plain and simple, if an "older" Christian is envious of a "new" Christian who was able to spend his life in debauchery, the "older" Christian pretty much has a love of the world and has let that love of the world hinder the fulfilment of the love of Christ.

1 John 2
15 Do not love the world or the things in the world. If anyone loves the world, the love of the Father is not in him. 16 For all that is in the world—the desires of the flesh and the desires of the eyes and pride in possessions—is not from the Father but is from the world. 17 And the world is passing away along with its desires, but whoever does the will of God abides forever.

Don't get blinded by what the world system tells us is desirable and fun, but look to the Lord for your fulfilment and joy.