In terms of discrimination and spoken prejudice, I view them as the same. So I would say Islamophobia, for example, is a form of racism (even if it technically called religious prejudice, not about race).
Although I think there is a difference and it depends on the person and the situation. So I personally think it’s okay to be against a religion in your own mind (hear me out!) Most - if not all - religions will have some aspects which not everyone will agree with and it may go against their moral beliefs. Hence you can’t blame people for being against it if they think the teachings/actions are “bad”.
THAT BEING SAID, thinking these things and actually saying them to people are two very different things. Often you can’t help how you feel about things (even if you try and pretend you can) but you can choose how you act. Especially seeing as you may not understand the religion properly. Asking a religious person about the topic and learning more or respectful debating is okay but discrimination and hate is not.
I think the main difference is that with racism, a person’s skin colour isn’t a moral issue, whereas religions have actions which could be viewed as morally good or bad.
^No offence to anyone - I am religious myself.