The Chofetz Chaim writes in Ahavas Chesed that doing chesed is what sanctifies us on This World. If so, why can’t that be enough to disconnect us from materialism? Why doesn’t doing chesed accomplish this too?
Answer:The goal is to use the physical world for the spiritual, but before we do that, we need to already develop the ability to disconnect from This World, and then we are able to sanctify physicality, such as through doing chesed. If a person doesn’t disconnect from materialism, he will end up becoming attached to This World even as he’s doing mitzvos. For example, there is a mitzvah of oneg Shabbos, but if a person is too attached to This World, he will end up becoming a glutton through oneg Shabbos. Therefore, we need to already develop beforehand the idea of disconnecting from materialism, so that we won’t become too attached to This World when we have to be involved in it for the sake of mitzvos.