system
Given the following post, respond as if you're commenting on Reddit:
human
[Stephen King's IT] Why does IT need Henry Bowers to kill the loser's club?

I'm assuming that it is explained better in the book, but why exactly does IT need Henry Bowers (this psychopathic 40-50 year old man) to help kill the loser's club. We've seen IT kill people before, mostly children, so it's not as if IT is incapable of killing people. 

My assumption is that, since IT's power comes partially from your belief in IT, and partially from your own mental weakness, IT isn't quite capable of killing an adult loser's club. The adult loser's club is mentally unstable and weak enough that IT can scare and appear before them, but they are mentally strong enough to not completely give themselves over to fear like they were as children, and therefore IT can't kill them just yet. Therefore, IT uses Henry Bowers, a completely mentally unstable individual, as a physical conduit to kill the loser's club.

Am I right in my assumption, or is there some other reason that is better explained in the book as to why IT needs Bowers?
gpt
The Losers can defeat IT by, in part, not being afraid.

An unstable adult human is not weakened by a Loser, or any other person, not being afraid of him.

Which are you more likely to have more genuine fear of? IT doesn't need for the Loser to be afraid of IT, IT feeds on the fear no matter where it comes from. If IT can add an additional element to instill genuine fear in the Losers, all the better. IT doesn't need Bowers to kill the Losers, just to create the credible threat.

If Bowers does kill any of the Losers, it's just a bonus.