Answer
Salam Dear Rafizal,
Thank you for your question and for contacting Ask About Islam.
Religion is often identified in the West, at least as a divisive force in history. It stands accused of being the root cause of many, if not most, wars. However, this picture of religion is not readily recognized in Islam and quite likely in many parts of the world. It is just that we are bombarded with Western culture and its preconceptions and prejudices.
The core value that all three religions you mention share is the value of spiritual reflection through which people should calmly contemplate questions about who we are, why are we here and what is our purpose in life. A religious person is above all, someone who cares about understanding these issues. He is someone who seeks meaning in life and a way of living a good life.
To build togetherness in this world among the major religions, what is needed is for this value to be foremost in our minds. We have to build on broad agreed foundations, which establish ease and generosity among people of different beliefs, but which do not compromise the claims made by each religion to be true.
Only in such an environment can real dialogue take place. This is where all parties are trying to explore the meaning of life and how we can best live up to it. In such an environment dialogue happens not to win material gain from someone else but to help each other gain beneficial knowledge.
In Islam we are taught that ‘religion is sincerity’. If we want to have an environment where people are free to seek a path to the true religion, then the thing that is needed above all is an environment where everyone is free to be sincere and are not compelled to accept ideas against their will.
As such, Islamic civilization historically established whole empires, which allowed a great degree of togetherness of people from many different religions. For more information on this topic read the answer: Religious Tolerance in Islam
I hope this helps answer your question.
Salam and please keep in touch.