It is difficult to think of a worse example than Islam or a religon generally for "uniting people".
Any attempt to unite people is inherently exclusionary. That is not problematic in itself but, inevitably, some people equate unity with superiority. It is a fine line.
What has improved (this is contentious) is: decline of religion, increased in shared interest, more diverse identities (i.e. people identify in more than one way), and more knowledge about people who are different with the internet/media/etc. Nationalism is, however, still understated as a cause of strife (I am in the UK so that perhaps colours my perspective).
Any attempt to unite people is inherently exclusionary. That is not problematic in itself but, inevitably, some people equate unity with superiority. It is a fine line.
What has improved (this is contentious) is: decline of religion, increased in shared interest, more diverse identities (i.e. people identify in more than one way), and more knowledge about people who are different with the internet/media/etc. Nationalism is, however, still understated as a cause of strife (I am in the UK so that perhaps colours my perspective).