I bear witness that there is no god (none worthy of worship) but Allah
Wa ash-hadu anna Muhammadan rasulullah.
And I bear witness that Muhammad is the messenger of Allah.
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This is the shahada, the declaration of faith. This declaration is all it takes to enter the path of Islam (The standard way is to do it in a mosque or Muslim gathering with witnesses, but that's not a must).
Islam is derived from the Arabic root "Salema": surrender, submission and obedience in peace and sincerity. In the deen* sense, Islam means submission to the will of God and obedience to His law.
Islam is perfect, sincere, applies to common sense and it is nothing new.
It's the same god as that of Adam, Noa AKA Nuh, Ibrahim AKA Abraham, Daoud AKA David, Musa AKA Moses, and Isa ib'n Mariam AKA Jesus son of Mary worshipped, peace be upon them all. Christians and Jewish people in Arab even call god Allah.
And Allah is the perfect term for referring to the one, unique creator of the heavens and the Earth, because the term literally cannot be pluralized in Arabic nor does it pertain to the male or female gender.
So, yeah, a bit of background knowledge aside... Allahu akbar!
*Deen: You way of carrying your faith, your lifestyle, the way you live and worship.