Humans have thirteen lives. Before reaching the final stage or making it to the promised paradise, all spirits must experience all those lives.
Some people don't believe in reincarnation, but it actually exists. To fulfill all stages of life, spirits transition from one body to another after death.
However, not all of them are fortunate enough to continue the cycle. All dead bodies require proper burial to have a spirit guide. Those spirits who haven't had the luxury of a funeral need an Apostle, known as a Shipper. Shippers have the power to give a spirit guide.
Unfortunately, I am a Shipper, and my job? Light a candle.