Some of the reasons why religion is hard to define include:
Religions vary significantly in terms of their beliefs, practices, and rituals, making it difficult to identify a single set of characteristics that all religions share.
Different people may have different understandings of what constitutes a religion, depending on their own cultural and personal perspectives.
Some people may consider certain belief systems or practices to be religious, while others may not. For example, some people may view atheism as a religion, while others may view it as the absence of religion.
Religion can be difficult to define because it often encompasses both individual and collective experiences, as well as both personal and social aspects.
Finally, religion is a dynamic and evolving concept, and different religions may change and adapt over time, making it difficult to define them in a fixed and static way.