In today's Gospel reading from Matthew 20, Jesus told the parable of the workers in the vineyard to his disciples. A landowner hired laborers to work in his vineyard at various times of the day and gave all of them the same pay in the evening. Those who had worked longer hours were not happy. The owner replied to one of them, "My friend, I am not cheating you. Did you not agree with me for the usual daily wage? Take what is yours and go. What if I wish to give this last one the same as you? Or am I not free to do as I wish with my money? Are you envious because I am generous?" Jesus again made the point that many "who are first will be last, and the last will be first."
Here are my thoughts. God is ready to give all of us eternal life at the end. Are we to grumble that he is not being fair? Once you are in heaven, are you still going to complain to God that some others you see up there had not worked as hard as you did in serving him on earth? There is no place in heaven for anyone who still harbors envy. So, be content with whatever you receive from the Lord and mind your own business. If God cannot please you, you won't ever be happy anywhere.