Religion is a Delusion/Mental Illness

[Angrboda]

Before 1973, the American Psychiatric Association classified homosexuality as a mental illness.  In 1973, they no longer classified homosexuality as a mental illness.  Nothing changed about homosexuality itself.  What changed were societal attitudes toward homosexuality.

What makes something a mental illness is its level of social acceptability.  

Religion in not considered to be a mental illness because it is socially acceptable.  Otherwise, it would be a mental illness.

Bullshit. This is a hasty generalization. Simply because some mental illness diagnoses may be the product of cultural prejudices does not justify the conclusion that they all are, nor its corollary that religion would be classified as a mental illness if it weren't socially acceptable. People believe all sorts of weird things, from alien abduction to contrails, without that belief rising to the category of mental illness.