Twenty-first century 'is' too strong, lepiej...could be considered) the age of globalisation. Many people (ale tutaj cos brakuje) emigrating to different countries for various reasons, for example economic, social OR political reasons. 'Around the world eliminates the boundaries' (ale kto? co? bo tylko moge sie domyslac), which allows easier access to other cultures. For this
reason, a lot of cultures are 'mixed together' (poszukaj inne slowa - to nie babka ktora mieszamy) to create an entirely new culture, characteristic of the new century.
There is a growing acceptance of other faiths OR nationalities. All
barriers disappear, 'the people closer' (tu cos brakuje, albo po prostu nie lubiesz uzywac niektorych slow) to one another, and try to understand 'each other their problems' (pomysl co tu napisales i popraw) against the background of social, religious( ale co? social, religious CO?)
Once, it was not possible, (to jest nieprawda, bo ludzie zawsze emigrowali nawet w 18tym, 19tym wieku) 'inter alia' (calkocicie nie rozumiem dlaczego to tutaj uzywasz- co to niby ma znaczyc?) due to the 'closure of the world' (ale world to nie sklep open-close), 'now' (zle miejsce) we are NOW more tolerant. As an example, you can certainly 'make' (zle slowo- poszukaj inne) the Poles working in England, where THERE are formed many associations of different cultures OR different religions. (Jak cos wymieniasz, i napewno tak samo jest po polski, to przed ostatnim slowem dajesz cos, albo 'and' albo 'or') Children of such 'compounds' (calkowicie zle slowo) have an easier start in life, often at an early age (kto? co, tutaj brakuje THEY are able to speak fluently in several languages. StayING abroad enables practical learning OF foreign languages, resulting in an 'additional opening to the world' (dobrze, ale w jaki sposob- po prostu jak?).
On the other hand we can see the 'wrong side of life' (popraw, niema czegos takiego, ) in a multicultural society.
In France, Muslims can not pray in public places, are partially discriminated against. (no i co? nie dokonczyles zdania)
Although we see progress towards the unification of the population, 'is' (nie rozumiem dlaczego uzyles to slowo, tutaj w zdaniu cos brakuje, ono nie jest gram) still often condemn other religionS or cultureS, while mocking them.
We should strive to understand other cultures, in keeping 'with their own' (with their own WHAT?). But (ale co? nie piszesz) only depends on us whether, in such a society will dominate the consent, or, 'therefore' (calkowicie zle slkowo tutaj), (tutaj cos brakuje) have many new conflicts.