Who is a Muslim?
A Muslim believes in one supreme God Allah who is his creator and sustainer to whom he will return by death. His prophet is Prophet Muhammad SAW who is a messenger of Allah. He believes in all other messengers like Abraham,Moses, Jesus.(peace be upon them) who were sent to a particular nation. He believes in all books sent by Allah like the torah,the injeel etc and follows Quran because Quran is sent for the whole of humanity and it is unaltered since the time it is revealed.
A Muslim believes on the day of resurrection and his purpose of life is the pleasure of Allah swt.
Sadly due to islamophobia industry , because of some unislamic terror groups with islamic names and because of ignorance of muslim themselves,muslims are portrayed in a despiced manner. But the truth of Islam is way of life and an answer to your question “Why do I exist :” Do not be judgemental about muslims.Do not try to judge Islam by the non practicing Muslims you see around you.Try to know how a muslim is supposed to be.
Here I made a simple infograph on who is a muslim wrt Quranic verses.Hope you will help me spread this khair and help remove the ignorance about Islam.