When that potential customer then asks you to tell them where they can go to get the service or product, and you flatly refuse to tell them, you are trying to force your beliefs on them.
Kind of a stretch there. It’s hard to imagine a situation where the information the potential customer is asking for isn’t easily available from a plethora of other sources.
I would agree with you in theory that a referral to another service provider doesn’t seem to be in conflict with anyone’s religous beliefs. But calling that an example of “forcing your beliefs on them” is a road too far, in my view.