Assalam-o-Alaikum!
Culture in my opinion is a combination of varoius practices that we do in routine to implement our idealogy(whatever it be) about the whole living in this world.
so the root is the idealogy about the life on the whole...which dictates or shapes much of the build-up of any culture.Now if this idealogy is based on the
universal principles of humanity considering every human to be equal no matter it's balck or white,Arab or non-arab,poor or rich,young or old,man or woman.Principles that don't put any discimination among humans on gounds of hatred,partialism,racism,faschism etc.These principles can't be formed by humans bcz potentialy they possess all the ills mentioned above.
Thus it becomes inevitable for the Divine to intervene

and show mercy on the mankind and to give the man a
perfect idealogy concerning everything about his life which HE used to do throughout the mans history giving guidences(in forms of books also) through the selected personalities chosen among humans..as we know them
Messengers of God.As the humans were not spread throughout the globe as they used to live in
descrete areas only.like Palestine,Syria,Iraq etc.and also there communication and interaction were not as much advanced as it's now.so more the population grows consequently the interaction and problems grow bigger and larger.ALLAH(S.W.T) knew all of this before so he descended a complete ideology.a complete way of life till the last day of this world.how it could be a complete and perfect guidence till eternity...bcz ALLAH has said that no messenger's now going to emerge in
any part of the world after my last mesenger MUHAMMAD(S.A.W.).
so with all this in view along with the fact that idealogy shapes the culture...now if every muslim living anywhere in this world..from Japan to America,From Australia to Canada,from Indonesia to Turkey, either he is in middle east or in EU...if the muslims follow with sincerity and
refined intentions this perfect and complete way of life then ALLAH would supress the
superfial factor of the
cultures and civilizations
this
superficial factor comes from apparent features of a persons life style.like a typical way of talking,wearing,eating,meeting,greeting.expressing emotions etc...all these vary from place to place,continent to continent.so if we have enough
Taqwa and not only
fear of ALLAH (coz later is a part of the first) we would surely respect each other even with these differences which most of the times seem very big differences just bcz of our lack of understanding and impatience and bcz of our habbit to cling to a decision before observing all aspects of an issue precisely.
So culture is a mere tool to implement the idealogy and it is bound to be shaped by the idealogy.stronger the idealogy more the culture becomes useful otherwise vice versa.

abu turaab.
(i'm sorry if you find my way of expressing to be imature).