For those who use god as the ultimate purpose, they do so by arguing that God is someone who is its own point. God can’t have a purpose outside itself. This argument however is problematic because it doesn’t stop us from asking why? Using God does not settle the question.
Can there really be something which gives point to everything else by encompassing it, but which couldn’t have, or need, any point by itself? Something whose point can’t be questioned from outside because there is no outside?
This is problematic simply because God does not exist.
This need for an ultimate meaning to rule everything, an objective absolute value, arises from moral absolutism.
References
Nagel, T. (1987). What Does It All Mean? A Very Short Introduction to Philosophy (1st ed.). Oxford University Press.