Generally speaking, profanity is language that is socially offensive. The reasons that the language might be offensive depends on the social makeup and norms of the group you're referring to. Sometimes those norms are driven by religion, sometimes they are driven by other factors, and sometimes it is a combination of reasons.

For example, you can find instances of social groups that:

1. are not religious, but recognize the concept of profanity.

2. do not recognize some slurs as profane.

3. are religious, but do not recognize the same profanity as other social groups that belong to the same religion.