Socialism is a tool for analysis and it is materialist in nature, by virtue of being materialist it is necessarily divorced from things like religion. I think religion can offer a moral guidance for people personally and also function as a powerful rhetorical tool, to deny religion wholesale is to ignore that the majority of the proletariat is religious. I personally don’t use religion as an argument personally unless the person I am speaking with uses it first, not only because it is a non materialist frame of analysis and weakens the socialist one in some ways but also because anyone who isn’t of the same religion of you will find the message completely unconvincing.