The world system have a corrupt system. People want to establish life in sinful thoughts and deeds. Many times Christians talk about the people that reject Jesus. It is true that the people that reject Jesus will not be rewarded for their actions. They need to repent from their sins and follow Jesus.
If a Christians lives in sin then they will lose their rewards in heaven. A Christian can't hide their sins from God. The good news is this. A true believer will desire to life for Jesus. When a person have Jesus in their heart then they should have a transformed life.