In order to understand Islam, one cannot view it as a religion according to the western idea of the term. According to the west, religion is a system of belief in a god who is entitled to worship and obedience on a personal level. The definition excludes God's laws being involved directly in politics, science, education and many other areas. Religion, although thought of by a minority in America as a Way of Life, in western thought and practice is a set of mystically inspired rules designed to offer mere spiritual comfort in ones destiny after death or personal trials, i.e. a crutch.
Islam is a complete way of life. The word Islam is Arabic meaning obedience to the One God and to gain peace. It reveals and guides humanity in every area, personal, national, societal, scientific etc. Since God created all of these things, and more, nothing is exempt from His Law. Even every atom in the cosmos is subjected to the laws of Islam (obedience to God). Mankind's duty is to worship God in everything he engages. Mankin's duty is to educate and discover God's great creation. His duty is to strive to glorify God as the mysteries of the Universe become revealed in his quest for knowledge. All of this is done in through Islam, "obedience to the One God".
Islam, thus, is not merely a religion. It is God's Way. It existed before mankind, during mankind and will exist after mankind. Mankind simply chooses to accept Islam (gaining peace through obedience and submission to God) or he chooses to reject it through vain innovations (as seen in many religions) or by outright denial (atheist belief).
The followers of Islam are called Muslims. The word Muslim is Arabic meaning "one who obeys God". All that exists in the Universe obeys God by following the Laws He set in place. The Earth, Stars, Galaxies, etc. all follow His Laws in Islam. Thusly, they are called Muslims. The Prophets, Adam, Abraham, Ishmael, Isaac, Moses, Jesus, Muhammad and others, all obeyed God in Islam and are called Muslims. Everything and everyone that obeys God is a Muslim and follows Islam. In the time of the Prophet Muhammad God officially declared in his Qur'an (Reading of His word revealed to Muhammad) that Islam is our religion! People mistakenly sought various religions, worshipping Prophets along with everything else thinkable to man, and God finally put His stamp of approval on the religion for mankind. God Himself said, "...This day have I perfected your religion for you, completed My favor on you, and have chosen for you Islam (in Arabic means Peace through the submission of your will to God) as your religion." Qur'an 5:3.
Islam, existing as a religion for mankind, directly instituted by God Himself, is thus defined in the Holy Qur'an, which was revealed to the last Prophet, Muhammad. When God said, "this day I have perfected your religion for you..." He made no doubt that the advent of Islam, as a religion, is the final revelation and He will give no other nor will He alter it. It has been perfected until the Day of Judgment. Muhammad is His last Messenger and no other will be sent with another message.
Exerpt from Dawah Binder by BrJimC 2000