One of the largest religions currently being practiced is Christianity, and they are the ones who believe in life immediately after death. Their belief is based loosely on the Jewish beliefs of heaven and rebirth, but they have their own system of faith that stems from the events after the death of Jesus Christ. While many different sects have come up with their own rules regarding this facet of their religion, all of them basically offer the concept of heaven for eternity for those who behave well in this life. It is an important part of their religious dogma, but it also provides a balance for those who choose to go against the religious practices of their time.
Getting into heaven is something the majority of Christians believe they will be able to do after life, and they have an entire set of steps that will help them do it. For those who are free of sin and life a perfect life, it is simply a matter of waiting until their physical body dies. They will be welcomed with open arms through the pearly gates, and they will reside in bliss for all of eternity.
It might seem to outsiders that only the good part of the afterlife is mentioned, but those who attend Christian worship services on a regular basis understand what will occur if they fail to follow the rules, life a sinful life, or even if they choose not to work for forgiveness of their sins. They will spend the eternity that remains after their death in hell, and there is not much chance they will ever escape.
There is a balance in Christianity between heaven and hell, and practitioners of the faith are encouraged to work for the best possible eternity. It is a religion that stresses forgiveness of confessed sins so that a person who errs can still achieve a good outcome after death, but it does promise punishment to those who fail to follow the rules.