Let's talk about different system which are part of this world in current era.There is system of democracy , dectetorship , Islamic system and many more .
Let's define Islamic system first , Islamic system is a complete code of life in which all the teachings of how to live life? How to deal with economy, politics and society is told. It's a complete system. In this system a person follows the commandments of Allah Almighty.A human being is caliph of Allah Almighty so a human being is in this world to live his life according to commandments of Allah Almighty and it's duty of human being to implement the laws of Allah Almighty in the society. But the non Muslims don't follow Islam they follow other system which is democracy.
Democracy mean "for the people by the people" In democracy a human being makes laws by himself and implement them . But it's not a right way because human being makes a lot of mistakes and as he is caliph of Allah so he has no right of making laws but non muslims have disobeyed and they are trying to do what they want so , now non muslims are not having any right to lead the world as caliph because they disobeyed and they tried to implement man made laws which contains a lot of flaws.
It's now duty of Muslims to implement the laws of Allah Almighty on the society. Because Islam is complete system so it covers every aspect of life . Allah Almighty is the one who knows everything better and there is success for human being in following the commandments of Allah Almighty so now Muslims have to perform their duties as caliphs of Allah Almighty. A Muslim has to implement the laws of Allah Almighty on the society then the life of people will become easy and every body will get equal rights. The life will become easy there will be justice there will be no difference of race, colour, country. Every Muslim will get equal rights so there is success for human being if he tries to follow the rules of Allah Almighty.
At the end I want to invite all the readers to study Islam do research and try to reach towards reality. A human being should think that why he is here in this world ? Who has created him ? What's the purpose of his/her life ? What will happen to him/her when he/she will die ? How to live this life ?If you are searching for reality, inner peace than study Islam . Islam explains everything in detail. What will happen after death it's also explained in detail.How to be successful in this life and hereafter?
If you are really interested in finding reality study Quran Pak ( The final testiment of Allah Almighty which was revealed on the last Prophet Hazrat Muhammad (P.B.U.H). And amazing thing about Quran Pak is that there is no change in it even though 1400 years have been passed. You will get the Quran with same wordings in every part of the world there is no change . So study Islam study Quran and try to prepare yourself for the day of judgement when you will be in front of Allah Almighty and you have to answer him what you have done in the worldly life .