Jesus compares salvation to a landowner who paid all his workers the same amount; those who worked all day, and those who only worked the last hour. In life, we are usually rewarded based on our effort. The harder and longer we work, the greater our rewards. And Jesus tells us in Matthew 19:29 that based on what we do in his name, we will be greatly rewarded in heaven. Here though, Jesus is talking about getting to heaven. God wants to give salvation to everyone; those who turn away from sin early in life, and those who repent late in life.
Lord, help me to rejoice and not be envious when someone turns to you and receives your gift of salvation.