Final answer:
The belief that improperly buried spirits would be shunned in Hades is true according to ancient Greek religious customs, highlighting the importance of burial rites.
Step-by-step explanation:
According to fifth century Greek religious beliefs, the statement that the spirit of the dead would be shunned in Hades if not buried properly is True. In ancient Greek culture, proper burial rites were considered essential for the dead to be accepted into the realm of Hades and avoid a dismal fate. Hence, it was believed that if a person was not buried according to the rites, their spirit could face exclusion or roam restlessly between worlds. This belief underscores the importance of rituals and customs surrounding death in classical Greek society.