Around five thousand years ago there was no religion or any other religious community. There were no Hindus, Muslims, Sikhs or Christians. The only religion was Mankind. Everyone had and has one religion, Mankind. But as the influence of Kalyug1 grew, we started developing differences among ourselves. The only reason was that the religious family (kul) gurus suppressed the truth written in the scriptures, whether the reason was selfishness or superficial ostentations.
As a result of which, today four religions and many other religious sects have been formed out of one Mankind religion. Consequently it is natural to have differences among each other. Prabhu / Bhagwan / Ram / Allah / Rab / God / Khuda / Parmeshwar of everyone is One. These are synonymous words in different languages. Everyone accepts that the Master of all is one, then why these different religious communities?