Numbers, Chapter 8 is about the Levites (pictured above). The Levites were the priestly class, designated by Yahweh to run the day-to-day activities of the Tabernacle. If the Israelites are Yahweh's favorite people, then the Levites are the favorites of the Israelites.
They had to be clean-shaven (except for the face), and that means they had to shave their pubes too! They (the males) went into the service of The Tabernacle at the age of 25 until 50 years old, when they were relieved of service.
They also had a lot of work cut out for them. As mentioned in a previous entry, the Levites were fairly busy people. They tore down and built up their portable temple (aka The Tabernacle), protected its holy relics, performed executions for breaking certain laws (or at least sentenced people to execution), performed animal sacrifices, purified the Israelites of their sins in elaborate rituals, followed very strict laws, and interpreted their scriptures, wrote them down, and ministered to the Israelites.
One might argue, from hindsight of course, that they weren't necessary to the function of society. But they were hardworking individuals, and they did serve some sort of function. They were kind of like the social glue that kept their tribes together.
Plus, without them, we wouldn't have these interesting historical documents from a 1000-plus years BCE to tell us about how weird and wacky and how utterly alien their culture was.