While the nation of France is most post-Christian in action, most people are Roman Catholic by tradition. They celebrate Christmas and Easter as important holidays.
Islam itself.
The premise of the question is incorrect. The Shahada IS actually the most important pillar of Islam.
Most countries with a Christian tradition. ( And probably a few that don't have such a tradition!)
without a shadow of doubt the most important & the greatest figure in Islam is the prophet Muhammad PBUH.
A number of religions developed out of Christianity. The most important of these is Islam.
The most important book of Islam is the holy book of Islam which is the Quran.
Three major traditions influenced the development of Islam. The most important was the monotheistic tradition of Judaism and Christianity. The next most important were the endemic Arab henotheist religions, like Rahmanists, and Arab monotheists, the Hanifs. The final group is Zoroastrianism.
Islam is most closely associated with the teachings of the Qu'ran. As with other religions such as Judaism and Christianity, Islam is a monotheistic religion. Its followers congregate and celebrate their supreme deity, Allah, and the teachings of their prophet, Muhammad.
The Holy Quaran
The most important person in Islam is Prophet Muhammad (saw). Muslims believe he is the Messenger of Allah. _Sincere Muslimah_
Most people say they celebrate the birth of Christ. When you ask most people this question they say Jesus' Birthday. However I have found that most people celebrate Christmas by giving gifts, and following their own family traditions. The problem with this is where does scripture fit into tradition. Hopes this helps