In the Qur'an, Allah says:
"We have sent you (Muhammad) as a mercy for all nations." [Al-Qur'an 21:107]
Thus Islam is not restricted to any particular race or nation, as many other religions are, but is universal, meaning that its message applies to all humanity, at all times, in all places.
Since Prophet Muhammad (peace be upon him) was the last prophet and messenger, his message applies to all future generations. All previous prophets, from Adam, Noah and Abraham to Moses and Jesus, were also Muslims:
"Not a single messenger did We send before you without this inspiration sent by Us to him - that there is no god but I, therefore worship and serve Me." [Al-Qur'an 21:25]
Since the Qur'an is the final testament, with every word and every letter unadulterated and unchanged, and protected by Allah from any change or tampering, it is the final revelation, and no other law will ever supersede it.
It applies, moreover, to every aspect of one's daily life, including personal, social, legal, economic, political, even military. Furthermore, Islam affects every part of the individual - physical, mental, emotional, and spiritual.