Muslims are the Islam Adopters, then to be Muslims :

"Belief Syahadatain : Belief Allah SWT is God AND Muhammad PBUH is The Messenger/Rasulullah"

Yeps, thats simple, but we talking about THE WORD BELIEF, NOT ONLY SAYING

while

to be known as Muslims Officially (=ID Card), i don't know more....

A PRELUDE II - There Levels of Everything

Yeps, there are levels of everything,

Why ?

IF a suspect already executed and dead, who would ressurect him/her/they ?

There are plenty POSITIVE WAYS to SUPPORT OUR RELIGION, there are :

being preachers, being scientists, being writings, singings, make songs, or only being a Good Muslims

There is prayers from Muhammad PBUH :

1. O Allah, Don't let Muslims Barricade got weak by Others (Granted)
=That's why Islam Adopters a the 2nd Majority Adopters AND almost everyone would Defend Islam IF Islam got disgraced (=Dinistakan)
2. O Allah, Don't let Muslims Barricade got Weak by Fear/Hunger/Natural Disasters (Granted)
=Thats why only since these 1-2 decades there are Natural Disasters Increases
3. O Allah, Don't let Muslims Barricade got Weak from Within (Not Granted)
=This Prayer isn't grant by Allah

SUMMARY

* There art 2 Nalar/Reasons of being a True Muslims 
** Tabayyun, is Finding Truth

** Make Peace among Societies of narrows (People with People)
* Islam is The Rightfull Religion, that's why there is 1 out of 3 of Prayers from Muhammad PBUH not grant


CONCLUSION

Islam is The Rightfull Religion, as Islam Adopters, THEE MUST having conscience toward All Creatures 
AND
That's why there is 1 out of 3 prayers of Muhammad PBUH not granted

May this writings could additional for THEE or at least my deed for Islam, Aamiin YRA...