Doesn't have to. Nothing in this life matters: Nihilism. There is no meaning to this life, for it is finite and transient: Nihilism.

Nothing in there says anything about the concept of infinite existence, infinite lives, omnimax deities. Doesn't need to. How you get to the Nihilistic conclusion doesn't really matter. "There's no life after this, so this finite life does not matter." is just as valid a path as "there's infinite life after this, so this finite life does not matter." Both are nihilistic, and both are encouraging you to do nothing to improve your current life, your current society, your current world.