How to be a Muslim?
The entire cosmos and and its creatures collectively belong to God. In this life people have the liberty in the choice of their faith. Therefore, there is no compulsion in religion. The right path has been explained to the people in a distinct way and they have also been shown how to differentiate between the right and wrong. One who turns away from evil and believes in good has come under God's protection.
It is in Quran - لَا إِكْرَاهَ فِي الدِّينِ ۖ قَدْ تَبَيَّنَ الرُّشْدُ مِنَ الْغَيِّ [There is no compulsion in religion; undoubtedly the right path has become distinct from the wrong.] (Al Baqara - 256)
It is a fact that the creator of this Cosmos is a single unitary God who has also created all creatures living in this Cosmos. Thus, it is a natural inclination for all of us, irrespective of race, ethnic background and geographical location to submit to our Creator God. Details in this context are available in a research paper titled ‘Religion: A Historical Perspective.’ In addition, the book titled ‘Is God really Merciful’, is an important read in this regard. Both, the research paper and the book, are available for free download.
Islam provides a specific way to submit to our Creator God. All that a person needs to do is to proclaim a Testimony of Faith (Shahada) in his heart, and if it is possible, by his mouth, which is saying ‘I testify that there is no God but Allah, the one only, without partner and I testify that Mohammad (صلى الله عليه و آله وسلم) is His servant and Apostle. (اشْهَدُ انْ لّآ اِلهَ اِلَّا اللّهُ وَحْدَه لَا شَرِيْكَ لَه وَ اَشْهَدُ اَنَّ مُحَمَّدً ا عَبْدُه وَ رَسُولُه).
For this purpose, you do not have to join any individual, group or organization in the world. You do not have to take any certificate from anyone or any organization in the world. This testimony is between you and your Creator Lord. However, if there are any faith related regulations/laws in the country of your residence, you must follow them with all sincerity.
The word Allah (اللّهُ) in Arabic means God. One should understand the true meaning of the Testimony (Shahadah - شهادة) which is detailed in the book titled ‘How to be a Muslim’, available for free download.
Unity in the world
There are two types of unity among people of the world.
Unity in living - Unity and care for each other, among the people of the world belonging to all regions, religions and ethnic background is mandatory. This is the only way to make our living in this world peaceful and prosperous.
Unity in faith - Unity in faith is not mandatory. What best we can do is to learn to appreciate each other for their individual faith. Many people have tried to impose their religion/faith by force on others in the history of mankind but have failed miserably.